Experimental investigation on the behavior of normal strength and high strength self-curing self-compacting concrete

Journal of Building Engineering 16 (2018) 79–93

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Experimental investigation on the behavior of normal strength and high strength self-curing self-compacting concrete

T

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M.M. Kamala, M.A. Safana, A.A. Bashandya, , A.M. Khalilb a b

Civil Engineering Department, Faculty of Engineering, Menoufia University, Egypt Civil Engineer, Menoufia, Egypt

A R T I C L E I N F O

A B S T R A C T

Keywords: Self-compacting Concrete Self-curing Concrete High-strength PEG LECA Flexure Beams

Self-compacting concrete is used when compaction of concrete is difficult to execute. To use a type of concrete, which does not need conventional curing, self-curing concrete can be used. The combination of those two types together provides a suitable solution for the curing and compacting processes. This research aims to study the feasibility of obtaining normal and high self-curing self-compacting concrete using different curing agents. The effects of curing agents on the behavior of normal and high-strength self-curing self-compacting concrete were studied. This research consists of two stages. The first stage conducted to investigate the effect of curing agent on the main properties of normal-strength and high-strength self-compacted concrete to obtain self-curing selfcompacting concrete. The main variables are; concrete grade, curing agent type, and dosage. The second stage was conducted to investigate the behavior of reinforced concrete beams cast using the suggested two concrete types. The results were driven in terms of initial cracking loads, ultimate loads, and crack patterns of testing beams. Results indicate that the both types used, normal-strength and high-strength self-curing self-compacting concrete are efficient in structural elements, which the curing and compacting processes are missing. Curing agents reduce the water evaporation from self-compacting concrete, and hence increase the water retention capacity of self-compacting concretes with sufficient hardened concrete properties.

1. Introduction Self-Compacting Concrete (SCC) is a highly workable type of concrete which has high performance and suitable strength. It can also flow under its own weight through restricted sections without segregation or bleeding [1,2]. SCC has substantial commercial benefits because of ease of placement in complex forms with congested reinforcement [2,3]. Generally, there are several approaches for developing economical SCC such as using high volumes of economical pozzolanas to reduce the cement content and use of low-cost high range water reducers [4]. Efficient curing improves the strength and durability of concrete. Concrete curing is a major challenge in the construction industry, especially in areas, which suffer from the shortage of water. Normal curing methods seem to be the best methods for curing giving maximum strength and durability [5]. Sometimes the sufficient curing conditions cannot be produced so, self-curing concrete is suggested in such cases. Self-curing or internal curing is a new technique that can be used to provide extra moisture in concrete for more effective cement hydration and reduced self-desiccation without the need to use conventional curing regimes [6–8]. The self-curing main concept is to

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reduce the evaporation of water from concrete and therefore increase the water retention capacity of the self-cured concrete when compared to conventional concrete by using chemical curing agents [6–8]. In zones with a shortage of water, sustainability of water can be achieved by using a suitable chemical curing agents for curing of concretes [8–10]. Another concept for internal curing is to use porous aggregates to act as internal reservoirs to provide water to concrete during hydration. The internal curing for concrete can be performed using several materials such as; lightweight coarse aggregate (LWA) (like Lightweight expanded clay aggregate (LECA), lightweight natural sand (LWS), wood powder) and chemical curing admixtures (like super-absorbent polymers (SAP) and shrinkage reducing admixture (SRA)) [10–13]. Shrinkage-reducing admixture (SRA) (like propylene glycol type and polyethylene glycol), based on the use of poly-glycol products in the concrete mixtures, has been recently advised to reduce the cracks in concrete structure caused by drying shrinkage. The mechanism of this admixture based on the reduction of the surface tension of the mixing water as a physical change rather than on a reduction of water evaporation [8,14–16]. Self-curing (SC) concrete with curing agents gives about 10% less compressive strength than normal water curing [17,18]. The

Corresponding author. E-mail address: [email protected] (A.A. Bashandy).

https://doi.org/10.1016/j.jobe.2017.12.012 Received 25 July 2017; Received in revised form 1 December 2017; Accepted 21 December 2017 Available online 23 December 2017 2352-7102/ © 2017 Elsevier Ltd. All rights reserved.

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main advantage of the SC is noticed when compared to those who are not cured. Also, SC resulted in better hydration processes with time under drying condition compared to conventional concrete. Water transport through SC is lower than air-cured conventional concrete. Sorptivity and permeability values for SC decreased with age due to lower permeable pores as a result of the continuation of the cement hydration [19]. The using of self-curing self-compacting concrete (SC-SCC) provides the benefits of both [20,21]. Curing agent type and dosage affects on SC-SCC behavior and performance [21,22]. Several researchers try to study the effect of curing agents on the performance of self-compacting concrete in order to obtain self-curing self-compacting concrete [17,23–26]. Durability is not affected much by using chemical compounds for curing [17,27]. Nearly, the performance of normal strength and high-strength conventional concrete and SCC are the same regardless the strength [28,29]. SCC and SC concrete with SAP have better flexural strengths, compared to self-compacting concretes and self-curing concretes with LWA [30]. The flexural behavior of reinforced concrete beams with chemical curing agents (such as PEG400) performed well compared to the conventional specimens [31]. This research aims to study the effects of using different types and dosages of curing agents with normal strength self-compacting concrete and high strength self-compacting concrete in order to have self-curing self-compacting concrete "SC-SCC". Also, it aims to study the behavior of reinforced SC-SCC beams cast using those curing agents.

Table 1 Physical properties of the sand used. Property

Value

Specific gravity Volumetric weight (t/m3) Voids ratio (%) % absorption (%)

2.58 1.72 32 0.7

Table 2. The coarse aggregate used is recycled aggregate (crushed red brick and crushed concrete compared to crushed dolomite with a maximum nominal size of 20 mm), which satisfies the (E.S.S 1109/2008) [33] as shown in Tables 3 and 4. The shape of these particles is irregular and angular with a very low percentage of flat particles. Drinkable clean water, fresh and free from impurities was used for mixing and curing the tested samples according to the Egyptian code of practice. Two types of admixtures are used. The first is a chemical admixture, while the second is pozzolanic admixture. A high range water-reducing (HRWR) admixture as superplasticizer under the brand name of (Sika ViscoCrete® −5930 L) by Sika Company was used to help in increasing the workability of concrete without an additional amount of water. It meets the requirements of ASTM C-494 Types G and F and BS EN 934 [11]. Its main properties are shown in Table 5. Silica fume imparts very good improvement to mechanical and chemical properties. It improves the durability of the concrete by reinforcing and improving the microstructure through filler effect and thus reduces segregation and bleeding. The silica fume used is a pozzolanic admixture, which contains a 95% of silica (SiO2) in the powder form. Silica fume of specific gravity 2.34 was used in this study. Physical and mechanical properties of the silica fume used are shown clearly in Table 6 as provided by the manufacturer. Two types of self-curing regimes were performed. The first was done by using chemical curing agents while the second is achieved by using LECA as internal reservoirs. The self-curing agent used in this study is Polyethylene glycol PEG400, PEG600 produced by Morgan Chemicals Pvt. Ltd in Egypt, as a chemical agent in a liquid form for internal curing of concrete. It is free of chlorides and produces an internal membrane, which protects and prevents fresh concrete against overrapid water evaporation. Table 7 showed the characteristics of Polyethylene glycol PEG400 and PEG600 as produced by the manufacturer. Light Expand Clay Aggregate "LECA" was produced in a rotary kiln at about 1200 °C. LECA was imported from the National Cement Company, Egypt. The properties of LECA were shown in Table 8. Two types of steel rebars were used in this investigation. The first is the mild steel of rounded plain bars, 8 mm diameter as stirrups and secondary steel. The second is the high tensile steel of 10 mm diameter as main reinforcement. Yield stress, ultimate stress, modulus-of-elasticity, and elongation were obtained by performing different tests. Test results are given in Table 9.

2. Research significance This research aims to study two main points. The first is studying the effects of using different types and dosages of chemical curing agents with normal strength and high strength self-compacting concrete in order to have self-curing self-compacting concrete. The second is to study the behavior of reinforced SC-SCC beams cast using this type of concrete. The main variables at the first stage of this investigation are; concrete grade (N.S.-SCC and H.S.-SCC), types of self-curing agent (PEG 400, PEG 600 and LECA), the dosage of curing agent (PEG 400 and PEG 600 as 1%, 2%, 3%, 4%, and 5% of the cement weight while LECA dosages are; 1%, 2%, 3%, and 4% of the cement weight). The main variables at the second stage are; concrete grade and curing agent type. The outputs of this study are experimental results that the researchers can assimilate and disseminate to judge and use this type of concrete. The innovation in this research is the comparative study of the properties and the behavior of the normal and high strength SC-SCC concrete mixes using different internal curing materials. The importance of this research is to provide sufficient data for the researchers and engineers that concerns in using normal strength or high strength SCC in the desert sites or such places which the concrete curing processes are difficult. 3. Materials and test specimens All tests in this research are carried out in the Construction Materials Laboratory in Civil Engineering Department, Faculty of Engineering, Menoufia University. The materials used are; the design of test specimens and testing procedures were discussed in the following sections.

3.2. Concrete and test samples The start point of choosing the proportions of self-compacted concrete was conducted firstly based on previous researchers [35–37]. Two mixes were used. The first is a normal strength self-compacted mix "NSSCC" while the second is a high-strength self-compacted mix "HS-SCC". The conducted experimental program divided into two stages. The first was performed to have the effect of curing agent on NS-SCC and HS-SCC mixes. The second part was performed to get the behavior of reinforced self-curing self-compacting concrete beams. The experimental program is shown in Fig. 1. To obtain the self-curing self-compacting concrete, the self-curing agents were added to the two self-compacted concrete mixes. The first

3.1. Materials The cement used is the ordinary Portland cement CEM I 52.5 N from the Misr Beni-Suef factory. It satisfies the Egyptian Standard Specification (E.S.S. 4756-1/2009) [32]. The fine aggregate used is the natural siliceous sand that satisfies the (E.S.S 1109/2008) [33] and ASTM C-33 [34]. It is clean and nearly free from impurities with a specific gravity 2.58 t/m3 and a fineness modulus of 2.72. Its mechanical properties are shown in Table 1 while its grading is shown in 80

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Table 2 Grading of the sand used according to (ASTM C-33). Sieve size (mm)

9.5 mm

4.75 mm

2.36 mm

1.18 mm

0.61 mm

0.31 mm

0.16 mm

% Passing ASTM C−33 % Passing sand used

100

95–100

80–100

50–85

25–60

5–30

0–10

100

97

91

81

41

14

4

Table 3 Physical properties of the dolomite used.

Table 6 The chemical components of the silica fume used (as provided by the manufacturer).

Property

Dolomite

Chemical Composition

SiO2

Al2O3

Fe2O3

CaO

MgO

SO3

K2O

L.O.I

Specific gravity Volumetric weight (t/m3) % Absorption (%) Aggregate crushing value (ACV) (%)

2.62 1.84 0.76 17.5

Average (%)

95.93

0.52

0.05

0.2

0.18

0.1

0.4

2.9

mentioned before. The tests illustrated in this section. At the first stage, the tests performed on fresh and hardened concrete according to European Code and Egyptian Code for self-compacting concrete [1,11]. At the second stage, beam flexure test was performed. The tests on fresh concrete were; slump test, J-ring, and Vfunnel test to gauge the self-compacting concrete characteristics. Standard slump cone was used to determine the workability of the concrete as shown in Fig. 3. The J-ring test aims for investigating both the filling ability and the passing ability of the SCC. Also, it can be used to investigate the resistance of SCC to segregation by comparing test results from two different portions of the sample. The J-ring test measures three parameters: flow spread, flow time T50J (optional) and blocking step. The J-ring flow spread indicates the restricted deformability of SCC due to blocking the effect of reinforcement bars and the flow time T50J indicates the rate of deformation within a defined flow distance. The blocking step quantifies the effect of blocking as shown in Fig. 4. The V-funnel flow time is the period a defined volume of SCC needs to pass through a narrow opening and gives an indication of the filling ability of SCC provided that blocking and/or segregation do not take place; the flow time of the V-funnel test is to some degree related to the plastic viscosity as shown in Fig. 5. The tests on hardened concrete were; compressive, tensile, flexure strengths. At the second stage, beam flexure test was performed. The load was applied (using 3-point load system) then increased by using a flexure testing machine (capacity of 100 kN). Two dial gauges of 0.01 mm accuracy and maximum capacity of 10 mm were used for deflection measurements at the middle and quarter points of the bottom surface as shown in Fig. 6. For strain measurements, one dial gauge with accuracy 0.01 mm and a maximum total record movement of 10 mm. Four demic points were fixed on the vertical longitudinal side of the beam as two rows. The first raw was fixed at 1.5 cm far from the upper edge, while the other raw was fixed at 1.5 cm from the lower edge of the beam. The distance between each two demic points in the same row was 20 cm as shown in Fig. 6. The results are driven in terms of initial cracking loads, ultimate loads, deflection values, strain values, crack numbers and crack pattern.

Table 4 Sieve analysis of the dolomite used. Sieve size (mm)

12.5 mm

9.51 mm

4.76 mm

2.38 mm

% Passing ASTM C−33 % Passing Dolomite used

90–100

40–70

0–15

0–5

95

52

10

2

mix of NS-SCC is chosen based on the previous research conducted by Etman, 2006 [35] while the second mix of HS-SCC is chosen based on the previous study conducted by El-Dieb, 2009 [36] as shown in Table 10. That performed to obtain the optimum value of curing agent to have a satisfied self-curing self-compacting concrete. In the first stage, two curing agents were used; chemical and porous aggregate. Polyethylene glycols PEG400 and PEG600 were used as chemical curing agents as 1%, 2%, 3%, 4%, and 5% of cement content. Also, LECA was used as internal reservoirs to help in internal curing process (as 1%, 2%, 3%, and 4% of cement content). They added to previously mention two concrete mixes (NS-SCC and HS-SCC). The specimens used in this study are cubes having the dimensions of 100 × 100 × 100 mm to determine the compressive strength. Cylinders with the dimensions of 100 × 200 mm cast to determine the tensile strength. Prisms with the dimensions of 100 × 100 × 500 mm cast to determine the flexural strength. In the second stage, the better ratios for each curing agent were chosen to cast reinforced self-curing self-compacting beam samples. In the second stage, two beams cast for each chosen optimum ratio of curing agents. Beams of dimensions 100 × 150 × 1000 mm used in the second stage. Its dimensions and reinforcement details are shown in Fig. 2. All the beams were tested under three-point static loading. The beams tested as a simply supported beam. Beams codes shown in Table 11. The results recorded and photographed. Results of deflection and strain values for each load increment, the initial cracking and failure load recorded. The number and the pattern of cracks traced for each load increment up to failure. Then the tested beams photographed to show the crack pattern.

4. Test results and discussions The results of this study derived in terms of compressive strength, tensile strength, and flexure strength at the first stage. At the second stage, when studying the behavior of reinforced concrete beams cast using this concrete type, the results derived in terms of initial cracking

3.3. Performed tests The experimental program was divided into two stages as Table 5 Technical information of SP (Viscocrete 5930 L) used (As provided by the manufacturer). Base

Appearance

Density

PH-value

Chloride content

Air entrainment

Compatibility

Aqueous solution of modified polycarboxylate

Turbid liquid

1.08 ± 0.005 kg/liter

7.0 → 9.0

Nil

Nil

All types of Portland cement

81

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Table 7 Technical information of Polyethylene Glycol "PEG400 and PEG600" used (as provided by the manufacturer). PEG type

Average molecular weight

Hydroxyl Number, mg KOH/g

Liquid Density, g/cc 20 °C

pH at 25 °C, 5% Aqueous solution

Average Number of Repeating Oxyethylene units

Melting or Freezing range °C

Solubility in Water at 20 °C, % by weight

Viscosity at 100 °C

PEG 400 PEG 600

380 to 420 570 − 630

264 to 300 178 − 197

1.1255 1.1258

4.5 – 7.5 4.5 – 7.5

8.7 13.2

4 to 8 15 − 25

Complete Complete

7.3 10.8

absorb the mixing water as well as the lower gravitation of light aggregates. That creates the weight of the particle resist the movement. Increasing LECA content decreases the flowability of this type of concrete. The recorded results of the high-strength SC-SCC are shown in Table 13. Increasing self-curing agent dosage increases the flowability of high strength SC-SCC. Using PEG400 is better than using PEG600 for high strength SC-SCC. Increasing LECA content increases the flowability of H.S.SC-SCC.

Table 8 Characteristics of light expanded clay aggregate (LECA) used (as provided by the manufacturer). LECA Grading

Density

Absorption of water

Lightning

Sound effect

Thermal effect

0–10 mm

≤ 710 kg/ m3

30–40%

Up to 30% of dead load

Sound insulation

Self-thermal 0.09 < ƛ < 0.101

Table 9 The test result of reinforcing bars (rebars) (due to test results).

4.2. Effect of using internal curing agents on the main mechanical properties

Steel type

Yield Stress (MPa)

Tensile Strength (MPa)

Elongation (%)

Modulus of Elasticity (GPa)

Mild Steel High Tensile Steel

295 365

409 530

22 13

2010 2010

The optimum obtained results for self-curing agent type and dosages for normal and high-strength SC-SCC illustrated in Figs. 7 to 15. The results obtained at 7, 28 and 56 days after cast. The optimum obtained value when using PEG400 was obtained at 3% (as a ratio of the cement content as an admixture) in the case of N.S.SC-SCC while the optimum value in the case of high-strength selfcuring self-compacting concrete H.S.SC-SCC is obtained at 2% of the cement weight. The optimum values of PEG600 obtained at 2% in the case of N.S.SC-SCC while the optimum value for H.S.SC-SCC obtained at 3% of the cement weight. The optimum obtained value when using LECA as an internal reservoir obtained at 3% of the cement content as an admixture in the case of N.S.SC-SCC while the optimum value in the case of H.S.SC-SCC was obtained at the percentage of 2% of the cement weight.

loads, ultimate loads, deflection values, strain values, and crack pattern. 4.1. Effect of using internal curing agents on fresh concrete properties The results of J-ring tests and V-funnel tests as slump flow tests of normal strength SC-SCC are shown in Table 12. Increasing self-curing agent dosage increases the flowability of normal strength SC-SCC satisfying previous researchers [12]. Using PEG600 as self-curing agent is better than using PEG400 and LECA for normal strength SC-SCC. Using LECA decreases the flowability. Results show a resistance to the flow than the control mix due to the presence of small pores which will

4.3. Effect of using internal curing agents on the behavior of RC beams Initial cracking loads and failure load is shown in Fig. 16. The Fig. 1. The flow chart of the experimental program.

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Table 10 Concrete mixes used "Stage (1)". Mix Type

Mix Code

Cement (kg/ m3)

W/C (kg/ m 3)

F.A. Sand (kg/ m3)

C.A. Dolomite (kg/ m3)

Silica fume (kg/ m 3)

Super-plasticizer (kg/ m3)

Curing Agent Type

Control “C” N.S.SC-SCC

H.S. SC-SCC

425 N-P4-1 N-P4-2 N-P4-3* N-P4-4 N-P4-5 N-P6-1 N-P6-2* N-P6-3 N-P6-4 N-P6-5 N-L-1 N-L-2 N-L-3* N-L-4 H-P4-1 H-P4-2* H-P4-3 H-P4-4 H-P4-5 H-P6-1 H-P6-2 H-P6-3* H-P6-4 H-P6-5 H-L-1 H-L-2* H-L-3 H-L-4

170 (40% C)

838

686

42.5 (10% C)

8.5 (2% C)

– PEG 400

PEG 600

LECA

900

243 (27% C)

664

444

157.5 (17.5% C)

18 (2% C)

PEG 400

PEG 600

LECA

Dosage as % of C

1% 2% 3% 4% 5% 1% 2% 3% 4% 5% 1% 2% 3% 4% 1% 2% 3% 4% 5% 1% 2% 3% 4% 5% 1% 2% 3% 4%

* Optimum values.

4.3.1. The initial cracking and ultimate loads Initial cracking loads and failure load are shown in Fig. 16. The average initial cracking loads of reinforced normal and high-strength SC-SCC beams are nearly behaving the same when using PEG400 and LWA but they increased when using PEG600 by about 12%. The average initial cracking loads of reinforced H.S.SC-SCC beams increased by about 11% compared to reinforced N.S.SC-SCC beams. The average recorded ultimate load values for reinforced N.S.SCSCC beams are nearly the same for the three curing agents used. In the case of H.S.SC-SCC, LWA was noticed as optimum one followed by PEG400 then PEG600 by a difference of about 2%.

Fig. 2. The details of the reinforced concrete beams.

Table 11 Beam coding "Stage (2)". Beam Name C

Beam Description Control Normal Strength Beam without any admixtures (Conventional reinforcing concrete beams)

N-P4

Normal Strength self-curing selfcompacting concrete N.S.SC-SCC

N-P6 N-L H-P4 H-P6 H-L

High Strength self-curing self-compacting concrete H.S.SC-SCC

4.3.2. Ductility ratio The ductility of the beam can be expressed based on the deflection of the beam through the displacement ductility/ductility index/deformability index, μ = Δu/Δy. According to ACI Committee 363 [38], the ductility index is defined as (μ= Δu/Δy) where Δu is beam deflection when a beam collapsed and Δy is beam deflection when longitudinal reinforcement yielded, according to Sung et al. [39]. The ductility ratio can be defined as the ratio of the curvature at the ultimate moment to the curvature at yield. The ductility indexes of all beams were listed in Table 14. In the case of normal strength SC-SCC, the ductility index of beams cast using PEG 400, PEG 600 and LWA increased by about 34.8%, 14.4%, and 24.1%, respectively compared to control beam. In the case of highstrength SC-SCC, the ductility index of control beam is higher than PEG 400, PEG 600 and LWA by about 15.6%, 17.6%, and 4.2%, respectively. From the Table, the experimental deflection ductility index ranges from 1.96 to 2.54. Generally, a high ductility index indicates that a structural member is able to largely deform prior to failure. Beams with a ductility index up to 2 lacked adequate ductility and cannot redistribute moment. Beams with a ductility index of 3–5 is considered imperative for adequate ductility, especially in the areas of seismic

N.S beam using PEG 400 N.S beam using PEG 600 N.S beam using L.W.A (LECA) H.S beam using PEG 400 H.S beam using PEG 600 H.S beam using L.W.A (LECA)

deflection values were obtained at mid (point A) and quarter (point B) lower surface of beam span. The results of deflection are shown in Figs. 17 to 26). The results of tensile and compressive strain values of tested beams are shown in Figs. 27 to 36. 83

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Fig. 3. Slump flow test.

load is relational to the deflection values at the center and at the quarter of the lower surface of the tested beam up to the appear of the first crack in both normal and high-strength SC-SCC. For testing beams, the load-deflection curves can be classified into three distinct zones; the first zone is the post-cracking zone up to the cracking point which continued up to the yielding point, and the post-yield zone, up to failure. At the initial stage, the stiffness of the beam showed almost identical histories at a low level of loading and up to the cracking load, as this stage is controlled by the tensile strength of concrete. The second zone showed a distinct behavior in the different beams. The slope of the curve in this zone is almost linear and of crucial importance in design, it is a direct function which represents the effective stiffness of the beam. Regarding the post-yield zone, the beams showed the ability to withstand higher load until failure. Figs. 17 and 18 show the behavior of beams cast using PEG400, PEG600, and LWA compared to control beams of normal strength SCSCC at points "A" (midpoint) and "B" (at the quarter of the beams). The recorded deflection values for reinforced N.S.SC-SCC beams show that the maximum-recorded deflection value was obtained when using PEG600 then using PEG400 followed by using LWA compared to control beams. That may refer to their stiffness and ductility ratios. Figs. 19 and 20 show the load-deflection relationships of beams cast using PEG400, PEG600, and LWA for H.S.SC-SCC compared to control beams of N.S.SC-SCC at points "A" and "B". The recorded deflection values for reinforced H.S.SC-SCC beams show that the maximum-recorded deflection value was obtained when using PEG400 then using PEG600 and finally using LWA. Based on the obtained results, using LWA (as LECA) is more efficient than using PEGs as curing agent with H.S.SC-SCC. That may because LWA acts as internal reservoirs to provide sufficient water to complete the hydration processes of H.S.SCSCC. Figs. 21 and 22 show the load-deflection relationships of N.S.SCSCC and H.S.SC-SCC beams when using PEG400 as a curing agent at points "A" and "B", respectively compared to control beam sample. The reinforced H.S.SC-SCC beams showed higher stiffness compared to reinforced N.S.SC-SCC beams at points "A" and "B". When using PEG600 as a curing agent, Figs. 23 and 24 show the load-deflection relationships of N.S.SC-SCC and H.S.SC-SCC beams at points "A" and "B", respectively compared to control beam sample. As used LECA as LWA to perform the internal curing, Figs. 25 and 26 show the load-deflection relationships of N. S. SC-SCC and H. S. SC-SCC beams at points "A" and "B", respectively compared to control beam sample. Values were nearly in accordance with (Muthukumar et al., 2015) [31]. Based on results, using PEG400 is suggested with N.S.SC-SCC while using LWA is suggested with H.S.SC-SCC due to their improvement.

Fig. 4. J-ring test.

Fig. 5. V-Funnel test.

Fig. 6. Deflecto-meters and strain gauge.

4.3.4. Strain values Fig. 27 shows the tensile-strain to load relationships of beams cast using PEG400, PEG600, and LWA compared to control beams of normal strength SC-SCC. It also shows that the modulus of elasticity of PEG400 is higher than PEG600, LWA, and control by about 26.4%, 36.9%, and 11%, respectively. The studying of the modulus of toughness shows that

design and redistribution of moments [40–42].

4.3.3. Deflection values The load-deflection curves of the different beams indicated that the 84

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Table 12 Main fresh concrete properties of normal strength SC-SCC (as obtained from tests). Mixes

C N-P4–1 N-P4–2 N-P4–3* N-P4–4 N-P4–5 N-P6–1 N-P6–2* N-P6–3 N-P6–4 N-P6–5 N-L−1 N-L−2 N-L−3* N-L−4

Slump Flow

J-Ring

V-Funnel

D (mm)

T50 cm (sec)

Tf (sec)

D (mm)

T50cm (sec)

Tf (sec)

H1-H2 (mm)

To (sec)

T5 min (sec)

850 725 745 775 795 830 790 800 810 825 825 810 790 780 780

2.17 2 2.07 1.85 2.19 2.17 2.18 1.89 2.07 2.09 2.13 2.37 2.77 2.04 2.8

34.07 17 28.57 28.87 30.38 35.29 37.36 34.02 36.49 32.19 33.84 34.09 35.59 35.09 36.94

840 710 730 750 775 800 770 790 800 810 810 800 780 770 720

2.2 2.62 3.2 1.95 2.2 2.25 2.43 2.21 2.19 2.06 2.26 2.27 2.46 2.53 2.97

35.12 20 36.08 37.51 37.52 35.82 37.77 34.94 36.69 33.63 33.98 34.55 36.18 37.06

4 7 7 6 5 5 7 6 5 4 4 6 5 4

3.3 5.24 8.5 3.69 5.04 5.23 5.8 5.61 5.3 5.03 4.52 5.9 6.1 6.26 6.3

4.41 3.95 5.15 3.99 6.2 5.61 6.2 4.98 5.4 5.28 5.88 6.1 6.2 6.3 6.55

38.36

4

* Optimum values based on their main mechanical properties. Table 13 Main fresh concrete properties of high strength SC-SCC (as obtained from tests). Mixes

H-P4–1 H-P4–2* H-P4–3 H-P4–4 H-P4–5 H-P6–1 H-P6–2 H-P6–3* H-P6–4 H-P6–5 H-L−1 H-L−2* H-L−3 H-L−4

Slump Flow

J-Ring

V-Funnel

D (mm)

T50 cm (sec)

Tf (sec)

D (mm)

T50 cm (sec)

Tf (sec)

H1-H2 (mm)

T (sec)

T5 min (sec)

920 930 930 950 990 830 845 860 900 920 810 840 860 900

2.06 2.05 2.03 2.05 2.02 2.2 2.17 1.95 1.84 1.8 2.15 2.08 1.95 1.9

50.17 49.14 50.3 51.2 51.8 38.6 40.16 42.16 43.16 45.7 39.4 40.16 40.85 41.05

910 915 910 940 980 820 830 850 875 980 860 900 920 950

2.07 2.07 2.06 2.09 2.04 2.2 2.2 2.15 2.07 1.95 2.4 2.15 2.05 1.9

51.29 50.16 51.17 51.9 51.9 40.7 42.36 44.29 46.17 48.25 39.6 40.8 41.15

4 3 3 2 2 5 5 4 3 3 4 3.5 3.5 3

4.5 4.2 3.6 3.4 3.2 2.85 2.7 2.6 2.05 1.96 2.7 2.55 2.4 2.3

5.3 5.1 4.8 4.6 4.4 3.16 2.95 2.8 2.3 2.17 3.2 3.15 2.95 2.7

41.9

* Optimum based on main mechanical properties.

Fig. 8. Compressive strength values for N.S.SC-SCC and H.S.SC-SCC samples when using PEG600.

Fig. 7. Compressive strength values for N.S.SC-SCC and H.S.SC-SCC samples when using PEG400.

toughness shows that the recorded value is nearly equal when using PEG600 and the control beams than using PEG400 and LWA by about 2%, and 2.2%, respectively. The strain hardening region of using PEG400 is nearly large than PEG600, LWA, and control. Fig. 29 shows the tensile-strain to load relationships of beams cast using PEG400, PEG600, and LWA with high-strength SC-SCC compared to control beams. It also shows that the modulus of elasticity of Control is nearly higher than PEG400, PEG600, and LWA by about 25.7%, 11.7%, and 33%, respectively. The studying of the modulus of

the recorded value is nearly equal when using PEG600 and the control beams than using PEG400 and LWA by about 2%, and 2.2%, respectively. The strain hardening region of using PEG600 is nearly large than PEG400, LWA, and control. Fig. 28 shows the compressive-strain to load relationships of beams cast using PEG400, PEG600, and LWA compared to control beams on normal strength SC-SCC. It also shows that the modulus of elasticity of LWA is higher than PEG400, PEG600, and control beams by about 5.4%, 7.7%, and 18%, respectively. The studying of the modulus of 85

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Fig. 9. Compressive strength values for N.S.SC-SCC and H.S.SC-SCC samples when using LECA.

Fig. 13. Flexure strength values for N.S.SC-SCC and H.S.SC-SCC samples when using PEG400.

Fig. 10. Splitting tensile strength values for N.S.SC-SCC and H.S.SC-SCC samples when using PEG400.

Fig. 14. Flexure strength values for N.S.SC-SCC and H.S.SC-SCC samples when using PEG600.

Fig. 11. Splitting tensile strength values for N.S.SC-SCC and H.S.SC-SCC samples when using PEG600.

Fig. 15. Flexure strength values for N.S.SC-SCC and H.S.SC-SCC samples when using LECA.

Fig. 12. Splitting tensile strength values for N.S.SC-SCC and H.S.SC-SCC samples when using LECA.

Fig. 16. Initial cracking loads and ultimate loads of N.S.SC-SCC and H.S.SC-SCC reinforced beam samples.

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Fig. 17. Load-deflection values for N.S.SC-SCC beams compared to conventional reinforced concrete beams "NSC beams" at mid-span "A".

Fig. 21. Load-deflection values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG400 at mid-span "A".

Fig. 18. Load-deflection values for N.S.SC-SCC beams compared to NSC beams at quarterspan "B".

Fig. 22. Load-deflection values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG400 at quarter-span "B".

Fig. 19. Load-deflection values for H.S.SC-SCC beams compared to NSC beams at midspan "A".

Fig. 23. Load-deflection values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG600 at mid-span "A".

Fig. 24. Load-deflection values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG600 at quarter-span "B".

Fig. 20. Load-deflection values for H.S.SC-SCC beams compared to NSC beams at quarterspan "B".

cast using PEG400, PEG600, and LWA with high-strength SC-SCC compared to control beams. It also shows that the modulus of elasticity of PEG600 is nearly higher than PEG400, LWA, and control beams by about 24%, 16.7%, and 31.7%, respectively. The studying of the modulus of toughness shows that the recorded value is higher when

toughness shows that the recorded value is higher when using LWA than using PEG400, PEG600 and control beams by about 1.5%, 2.4%, and 19%, respectively. The strain hardening region of using LWA is nearly large than PEG400, PEG600 and control beams. Fig. 30 shows the compressive-strain to load relationships of beams 87

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Fig. 25. Load-deflection values for N.S.SC-SCC and H.S.SC-SCC beams when using LECA at mid-span "A".

Fig. 29. Load-tensile strain values for H.S.SC-SCC beams compared to NSC beams.

Fig. 26. Load-deflection values for N.S.SC-SCC and H.S.SC-SCC beams when using LECA at quarter-span "B".

Fig. 30. Load-compressive strain values for H.S.SC-SCC beams compared to NSC beams.

Fig. 27. Load-tensile strain values for N.S.SC-SCC beams compared to NSC beams. Fig. 31. Load-tensile strain values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG400 compared to NSC beams.

Fig. 28. Load-compressive strain values for N.S.SC-SCC beams compared to NSC beams.

Fig. 32. Load-compressive strain values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG400 compared to NSC beams.

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Fig. 33. Load-tensile strain values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG600 compared to NSC beams.

Fig. 36. Load-compressive strain values for N.S.SC-SCC and H.S.SC-SCC beams when using LECA compared to NSC beams.

Table 14 Initial cracking load, ultimate loads, and displacement ductility ratios for tested beams. Beam

Control N-P4 N-P6 N-L H-P4 H-P6 H-L

Fig. 34. Load-compressive strain values for N.S.SC-SCC and H.S.SC-SCC beams when using PEG600 compared to NSC beams.

Load (kN)

Pcr / Pu

Avg.* Initial Cracking Load (Pcr)

Avg.* Ultimate Load (Pu)

10 10 8 9 11 12 10

51.75 53.5 52.4 52.75 64.07 63.41 65.28

0.19 0.19 0.15 0.17 0.17 0.19 0.15

Displacement (mm) Δy

Δu

13.8 14.2 15.8 15 18.4 19 19.4

25.9 36 34 35 40 42 38

Displacement Ductility Ratio (Δu/Δy)

1.88 2.54 2.15 2.33 2.17 2.21 1.96

* The listed values are the average values for each two similar beam samples.

the modulus of elasticity of is higher when using Normal PEG400 than High PEG400 and control beams by about 3.5%, and 13.2%, respectively. The studying of the modulus of toughness shows that the recorded value is higher when using PEG400 on H.S than using PEG400 on N.S and control beams by about 19.3%, and 17.7%, respectively The strain hardening region of using PEG400 on N.S is nearly large than PEG400 on H.S. and control beam. Fig. 33 shows the tensile-strain values for the relationship of beams cast using PEG600 on normal strength SC-SCC compared to using PEG600 on high-strength SC-SCC and control beams. It also shows that the modulus of elasticity of control beam is nearly higher than both normal and high-strength SC-SCC using PEG600 by about 17.3%, and 11.7%, respectively. The studying of the modulus of toughness shows that the recorded value is higher when using PEG600 on H.S than using PEG600 on N.S and control beams by about 17%. The strain hardening region of using PEG600 on N.S is nearly large than PEG600 on H.S. and control beams. Fig. 34 shows the compressive-strain to load relationships of beams cast using PEG600 on normal strength SC-SCC case compared to using PEG600 on high-strength SC-SCC and control beams. It also shows that the modulus of elasticity of PEG600 on H.S is nearly higher than PEG600 on N.S and control beam by about 17% for both. The studying of the modulus of toughness shows that the recorded value is higher when using PEG600 on H.S than using PEG600 on N.S and control sample by about 8.7%. The strain hardening region of control beam is nearly large than both PEG600. Fig. 35 shows the tensile-strain to load relationships of beams cast using LWA with normal strength SC-SCC compared to using LWA with high-strength SC-SCC and control beams. It also shows that the modulus of elasticity of control beam is nearly higher than both normal and high strengths SC-SCC cast using LWA by about 29%, and 33%, respectively.

Fig. 35. Load-tensile strain values for N.S.SC-SCC and H.S.SC-SCC beams when using LECA compared to NSC beams.

using LWA than using PEG400, PEG600 and control beams by about 1.5%, 2.4%, and 19%, respectively. The strain hardening region of using LWA is nearly large than PEG400, PEG600, and control beam. Fig. 31 shows the tensile-strain values for the relationship of beams cast using PEG400 on normal strength SC-SCC compared to using PEG400 on high-strength SC-SCC and control beams. It also shows that the modulus of elasticity of PEG400 on N.S is nearly higher than PEG400 on H.S and control beams by about 34%, and 11%, respectively. The studying of the modulus of toughness shows that the recorded value is higher when using PEG400 on H.S than using PEG400 on N.S and control beams by about 19.3%, and 17.7%, respectively. The strain hardening region of using control beam is nearly large than both PEG400. Fig. 32 shows the compressive-strain to load relationships of beams cast using PEG400 on normal strength SC-SCC case compared to using PEG400 on high-strength SC-SCC and control beams. It also shows that 89

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Fig. 37. Crack patterns for control beam.

Fig. 38. Crack patterns for normal strength SC-SCC Beam when using PEG400.

Fig. 39. Crack patterns for normal strength SC-SCC Beam when using PEG 600.

Fig. 40. Crack patterns for normal strength SC-SCC Beam when using L.W.A.

modulus of elasticity of both normal and high strengths SC-SCC cast using LWA are higher than control beams by about 18%. The studying of the modulus of toughness shows that the recorded value is higher when using LWA with H.S than using LWA with N.S and control sample by about 20.8%, 19%, respectively. The strain hardening region of using LWA with H.S is nearly large than LWA with N.S. and control beam.

The studying of the modulus of toughness shows that the recorded value is higher when using LWA with H.S than using LWA with N.S and control beams by about 20.8%, and 19%, respectively. The strain hardening region of using LWA with H.S is nearly large than LWA with N.S. and control beams. Fig. 36 shows the compressive-strain to load relationships of beams cast-using LWA with normal strength SC-SCC compared to using LWA with high-strength SC-SCC and control beams. It also shows that the 90

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Fig. 41. Crack patterns for high strength SC-SCC Beam when using PEG400.

Fig. 42. Crack patterns for high strength SC-SCC Beam when using PEG600.

Fig. 43. Crack patterns for high-strength SC-SCC Beam when using LECA as L.W.A.

loading stages. Crack pattern of high-strength SC-SCC beams indicated that the failure modes of all tested beams are a flexural failure and flexure-shear failure with a nearly equal crack width. In addition, the number of cracking is nearly the same when using PEG600 and LWA. For PEG400, the number of cracks is fewer than that noticed for PEG600 and LWA. The number of cracks of normal strength SC-SCC is higher than high-strength SC-SCC due to the higher ductility of normal strength SCSCC beams.

4.3.5. Crack pattern The crack patterns of all tested beams were recorded then they were illustrated at each load increment up to failure. After that, they were photographed. Generally, all tested beams in this investigation are failed in flexure. The number of cracks in normal strength SC-SCC beams increased during loading stages. Figs. 37–40 show the crack pattern for normal strength beams. Crack pattern of normal strength SC-SCC beams indicated that; some of the beam samples failed by flexural failure (yielding of steel) with just vertical cracks. Other beam samples failed by flexure-shear failure. Its cracks normally initiates in the vertical direction and as increasing the load, it moves in an inclined direction due to the combined effect of shear and flexure then the cracks propagate to top and the beam splits. But for flexural failure. The width of cracks is nearly equal. The number of cracks when using PEG600 is higher than using PEG400, LWA, and control beam. Figs. 41 to 43 show the crack pattern for high-strength beams. The number of cracks in high-strength SC-SCC beams increased during

5. Conclusions In this research, a series of experiments have been performed to investigate the behavior and the properties of self-curing self-compacting concrete. Based on the experimental results presented in this paper, the following conclusions could be drawn as follow: 1. The main properties of self-curing self-compacting concrete depend 91

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2.

3.

4.

5.

6.

7.

8.

on the type of curing agent, especially when the workability and flowability of this type of concrete is considered. For normal-strength self-curing self-compacting concrete N.S.SCSCC, using PEG600 is more efficient than using PEG400 followed by using LECA as lightweight aggregate "LWA". For high-strength selfcuring self-compacting concrete, it is recommended to use LECA than using chemical agents. When using chemical agents, it is preferable to use PEG400 than using PEG600. The optimum obtained value when using PEG400 is obtained at 3% and 2% (as a ratio of the cement content as an admixture) for N.S.SCSCC and H.S.SC-SCC, respectively. When Using PEG600, the optimum values obtained at 2% and 3% for N.S.SC-SCC and H.S.SCSCC, respectively. In the case of using LECA, the optimum values obtained at 3% and 2% for N.S.SC-SCC and H.S.SC-SCC, respectively. The recorded deflection values for reinforced N.S.SC-SCC beams at points "A" and "B" (midpoint and quarter of the beams, respectively) showed that the maximum-recorded deflection value obtained when using PEG600 than using PEG400 and LECA. For reinforced H.S.SCSCC beams, the maximum-recorded deflection values obtained when using LECA compared to using PEG400 and PEG600. The initial cracking loads of reinforced normal-strength and highstrength SC-SCC beams are nearly the same for PEG400 and LECA but they increased when using PEG600 by about 12%. For reinforced H.S.SC-SCC beams, initial cracking loads increased by about 11% compared to reinforced N.S.SC-SCC beams. The recorded ultimate load values for reinforced N.S.SC-SCC beams are nearly the same for the three curing agents used. In the case of H.S.SC-SCC, LECA noticed as better one followed by PEG400 then PEG600. The crack pattern of both N.S.SC-SCC and H.S.SC-SCC showed that the failure modes of all tested beams are the flexural failure and flexure-shear failure. The number of cracks in the case of N.S.SC-SCC when using PEG600 is higher than that when using PEG400, LECA, and control beam. In the case of H.S.SC-SCC, the number of cracks is nearly the same when using PEG600 and LECA. For PEG400, the number of cracks is less than that noticed for PEG600 and LECA.

[2] ASTM.C-494, Chemical Admixtures, American Society for Testing and Materials ASTM International, Philadelphia, USA, 2003. [3] H.A. Mohamed, Effect of fly ash and silica fume on compressive strength of selfcompacting concrete under different curing conditions, A Shams Eng. J. no. 2 (2011) 79–86. [4] G.S. Rampradheep, M. Sivaraja, Experimental investigation on self-compacting selfcuring concrete incorporated with the light weight aggregates (no. spe2, pp. 1spe11), Braz. Arch. Biol. Technol. 59 (2016) (no. spe2, pp. 1-spe11). [5] M. Ravikumar, C. Selvamony, S. Kannan, B. G..S, self-compacted self-curing Kiln ash concrete, Int. J. Des. Manuf. Technol. 5 (1) (2011). [6] D.P. Bentz, P. Lura, J.W. Roberts, Mixture proportioning for internal curing, Concrete Int. 27 (2) (2005) 35–40. [7] V. Bilek, Z. Kersner, P. Schmid, T. Mosler, The possibility of self-curing concrete, in: Proceedings of the International Conference of Innovations and Developments in Concrete Materials and Construction, UK, 2002. [8] A.S. EL-Dieb, S.H. Okba, Performance of Self Curing Concrete, Ain Shams University, Cairo, Egypt, 2005. [9] B. Mather, Self-curing concrete, why not? Concrete Int. 23 (1) (2001) 46–47. [10] M.A. Safan, A.A. Bashandy, M.R. Afify, A.M. AboZed, Influence of curing conditions on the behavior of reinforced self-curing slabs containing super absorbent polymers, in: Proceedings of the 9th Alexandria International Conference on Structural and Geotechnical Engineering, Alexandria, 2016. [11] A.A. Bashandy, N.N. Meleka, M.M. Hamad, Comparative study on the using of PEG and PAM as curing agents for self-curing concrete, Challenge J. Concr. Res. Lett. 8 (1) (2017) 1–10. [12] B.M. Joseph, Studies on properties of self-curing concrete using poly-ethylene glycol, J. Mech. Civil. Eng. IOSR-JMCE (2016) 12–17. [13] M.I. Mousa, M.G. Mahdy, A.H. Abdel-Reheem, A.Z. Yehia, Self-curing Concrete types; water retention and durability, Alexandria Eng. J. 54 (3) (2015) 565–575. [14] K. Kovler, A. Bentur, S. Zhutovsky, Efficiency of lightweight aggregates for internal curing of high strength concrete to eliminate autogenous shrinkage, Mater. Struct. J. 34 (246) (2002) 97–101. [15] M.R. Geiker, D.P. Bentz, O.M. Jensen, Mitigating autogenous shrinkage by internal curing, High-Perform. Struct. Lightw. Concr. Acids SP-218 Am. Concr. Inst. (2004) 143–154. [16] T.A. Hammer, O. Bjontegaard, E.J. Sellevold, Internal curing role of absorbed water in aggregates: high-performance structural lightweight concrete, ACI Fall Conv. Acids SP 218 (2002). [17] A. Anantrao-Patil, M.R. Vyawahare, Comparative study on durability of self cured SCC and normally cured SCC, Int. J. Sci. Res. Eng. Technol. (IJSRET) 3 (8) (2014) 1201–1208. [18] A.A. Bashandy, Performance of self-curing concrete at elevated temperatures, Indian J. Eng. Mater. Sci. 22 (2015) 93–104. [19] A.S. Dieb, Self-curing concrete: water retention, hydration and moisture transport, Constr. Build. Mater. J. 21 (2007) 1282–1287. [20] M.S.R. Chand, P.S.N. Ratna-Giri, P.R. Kumar, G.R. Kumar, C. Raveena, Effect of self curing chemicals in self compacting mortars (March 2016), Constr. Build. Mater. 107 (15) (2016) 356–364. [21] M.J. Oliveira, A.B. Ribeiro, F.G. Branco, Curing effect in the shrinkage of a lower strength self-compacting concrete (Sep. 2015), Constr. Build. Mater. 93 (15) (2015) 1206–1215. [22] I. Türkmen, A. Kantarcı, Effects of expanded perlite aggregate and different curing conditions on the physical and mechanical properties of self-compacting concrete, Build. Environ. 42 (6) (2007) 2378–2383. [23] J.P. Nanak, A.K. Verma, R.B. Darshana, Comparison between mechanical properties of M30 grade self compacting concrete for conventional water immersion and few non-waterbased curing techniques, Int. J. Eng. 3 (2) (2013) 265–272. [24] C. Selvamony, M.S. Ravikumar, S.U. Kannan, S. Basil Gnanappa, Development of high strength self-compacted self-curing concrete with mineral admixtures, Int. J. Des. Manuf. Technol. 3 (2) (2009) 103–108. [25] B. Vidivelli, T. Kathiravan, T. Gobi, Flexural behaviour of self-compacting and selfcuring concrete beams, Int. J. Eng. Math. Comput. Sci. 1 (2) (2013) 64–77. [26] A.S. Raj, N. Yogananda, Experimental investigation on self-curing self-compacting concrete by replacing natural sand by M-sand and coarse aggregates by light weight aggregate for M-40 grade concrete, Int. J. Sci. Res. Publ. 4 (8) (2014). [27] A.A. Bashandy, Self-curing concrete under sulfate attack, Arch. Civil. Eng. 62 (2) (2016). [28] L.A. Qureshi, I.A. Bukhari, M.J. Munir, Effect of Different Curing Techniques on Compressive Strength of High Strength Self Compacting Concrete, Bahaudin Zakriya University, Multan, 2010. [29] S. Zhutovsky, Curing of high strength concrete to eliminate Autogenous shrinkage, Materials Struct. 35 (2012) 97–101. [30] B. Vivek, W.P. Bhavana, Prema-Kumar, M.T. Prathap-Kumar, Experimental investigation on properties of self-compacting and self-curing concrete with silica fume and light weight aggregates, Int. J. Eng. Res. Technol. (IJERT) 4 (6) (2015). [31] P. Muthukumar, K. Suganya-Devi, Flexural behaviour of self-compacting self-curing concrete beam, Int. J. Eng. Technol. Sci. IJETS 2 (4) (2015) 2349–3976. [32] E.S.S.4756-1, Portland Cement, Ordinary and Rapid Hardening, Ministry of Industry, Cairo, Egypt, 2009, p. 2009. [33] E.S.S.1109/, Aggregate, Ministry of Industry, Cairo, Egypt, 2008, p. 2008. [34] ASTM.C-33, Aggregates, American Society for Testing and Materials ASTM International, Philadelphia, USA, 2003. [35] Z.A. Etman, The Production and Properties of Self-compacted Concrete, Menoufia: f. of Engineering, Menoufia University, Egypt, 2006. [36] A.S. EL-Dieb, Mechanical, durability and microstructural characteristics of ultrahigh-strength self-compacting concrete incorporating steel fibers, Mater. Des. 30

Finally, normal-strength self-curing self-compacting and highstrength self-curing self-compacting concrete can be obtained by adding a suitable dosage of internal curing additive on the conventional selfcompacting concrete mixes. N.S.SC-SCC and H.S.SC-SCC are efficient in structural elements, which the curing and compacting are difficult or missing. To obtain better workability with sufficient strengths, PEG400 as a self-curing agent is recommended for normal strength SC-SCC while PEG600 is recommended for high strength SC-SCC as chemical curing agents. Curing agents (such as PEG 400, PEG 600) are used to reduce the water evaporation from self-compacting concrete while LECA acts as internal water reservoirs/tanks in concrete, and hence increase the water retention capacity of self-compacting concretes. Acknowledgement We avail this opportunity to express our deep sense of gratitude and wholehearted thanks to the laboratory of Properties and Testing of Materials at the Faculty of Engineering, Menoufia University to present and complete this work. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. References [1] The-European-Project-Group, Specification and guidelines for self-compacting concrete, in: European Federation of Producers and Applicators of Specialist Products for Structures (EFNARC), 2005.

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flexural behavior of high-strength concrete beams, Eng. Struct. 22 (5) (2000) 413–423. [41] M.A. Rashid, M.A. Mansur, Reinforced high-strength concrete beams in flexure, ACI Struct. J. 102 (3) (2005) 462–471. [42] S. Iffat, K. Maina, M.A. Noor, Member ductility experiment with high strength steel and concrete, in Proceedings of the 4th Annual Paper Meet and 1st Civil Engineering Congress, Dhaka, Bangladesh, 2011.

(2009) 4286–4292. [37] A.M. Khalil, Feasibility of Using Advanced Curing Techniques on the Behavior and Strength of Concrete Elements, Menoufia: (M.Sc.), Menoufia University, 2015. [38] ACI-363-07, Guide to Quality Control and Testing of High-Strength Concrete, American Concrete Institute (ACI Committee), Detroit, USA, 2007. [39] S. Sung-woo, K. Satyendra, Ghosh, J. Moreno, Flexural ductility of ultra-highstrength concrete members, ACI Struct. J. 4 (1995) 394–400. [40] S.A. Ashour, Effect of compressive strength and tensile reinforcement ratio on

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