Effect of internal curing on performance of self-compacting concrete by using sustainable materials

This paper is devoted to investigate the effect of internal curing technique on the properties of self-compacting concrete. In this study, self-compacting concrete is produced by using limestone powder as partial replacement by weight of cement with percentage of (5%), sand is partially replaced by volume with saturated fine lightweight aggregate which is thermostone aggregate as internal curing material in three percentages of (5%, 10%, 15%) for self-compacting concrete, and the use of two external curing conditions which are water and air. The experimental work was divided into three parts: in the first part, the workability tests of fresh self-compacting concrete were conducted. The second part included conducting compressive strength test and modulus of rupture test at ages of (7, 28 and 90) days. The third part included doing the shrinkage test at age of (7, 14, 21, 28) days. The results show that internally cured self-compacting concrete has the best workability and the best properties of hardened concrete which include (compressive strength, modulus of rupture) of externally cured self-compacting concrete with both water and air as compared with reference concretes. Also, the hardened properties of internally cured self-compacting concrete with percentage of (5%) with thermostone aggregate is the best as compared with that of percentages (10% and 15%) in both external curing conditions. In general, the results of shrinkage test have shown reduction in shrinkage of internally cured self-compacting concrete as compared with reference concretes and this reduction increases with increase in the thermostone aggregate content-within-self-compacting-concrete.

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Artificial Neural Network Estimation of the Effect of Varying Curing Conditions and Cement Type on Hardened Concrete Properties

Buildings ◽

10.3390/buildings9010010 ◽

2019 ◽

Vol 9 (1) ◽

pp. 10 ◽

Cited By ~ 1

Author(s):

Gökhan Kaplan ◽

Hasbi Yaprak ◽

Selçuk Memiş ◽

Abdoslam Alnkaa

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Limestone Powder ◽

Mineral Admixtures ◽

Hardened Concrete ◽

Slag Cement ◽

Curing Conditions ◽

Concrete Properties ◽

Concrete Production ◽

Artificial Neural

The use of mineral admixtures and industrial waste as a replacement for Portland cement is recognized widely for its energy efficiency along with reduced CO2 emissions. The use of materials such as fly ash, blast-furnace slag or limestone powder in concrete production makes this process a sustainable one. This study explored a number of hardened concrete properties, such as compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, water absorption and depth of penetration under varying curing conditions having produced concrete samples using Portland cement (PC), slag cement (SC) and limestone cement (LC). The samples were produced at 0.63 and 0.70 w/c (water/cement) ratios. Hardened concrete samples were then cured under three conditions, namely standard (W), open air (A) and sealed plastic bag (B). Although it was found that the early-age strength of slag cement was lower, it was improved significantly on 90th day. In terms of the effect of curing conditions on compressive strength, cure W offered the highest compressive strength, as expected, while cure A offered slightly lower compressive strength levels. An increase in the w/c ratio was found to have a negative impact on pozzolanic reactions, which resulted in poor hardened concrete properties. Furthermore, carbonation effect was found to have positive effects on some of the concrete properties, and it was observed to have improved the depth of water penetration. Moreover, it was possible to estimate the compressive strength with high precision using artificial neural networks (ANN). The values of the slopes of the regression lines for training, validating and testing datasets were 0.9881, 0.9885 and 0.9776, respectively. This indicates the high accuracy of the developed model as well as a good correlation between the predicted compressive strength values and the experimental (measured) ones.

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BEHAVIOR OF M 50 GRADE SELF-COMPACTING CONCRETE DEVELOPED USING PORTLAND SLAG CEMENT AND METAKAOLIN

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2019.27 ◽

2019 ◽

Vol 6 (1) ◽

Author(s):

Sravya Nalla ◽

Janardhana Maganti ◽

Dinakar Pasla

Keyword(s):

Compressive Strength ◽

Mineral Admixtures ◽

Partial Replacement ◽

Test Results ◽

Slag Cement ◽

Self Compacting Concrete ◽

Destructive Testing ◽

Compressive Strength Test ◽

Portland Slag Cement ◽

Strength And Durability

Self-compacting concrete (SCC) is a revolutionary development in concrete construction. The addition of mineral admixtures like metakaolin, which is a highly reactive pozzolana to the SCC mixes, gives it superior strength and durability. The present work is an effort to study the behavior of M50 grade SCC by partial replacement of Portland Slag Cement (PSC) with metakaolin. Its strength and durability aspects are comparable with a controlled concrete (without replacement of cement). In the present work, a new mix design methodology based on the efficiency of metakaolin is adopted. The optimum percentage replacement of cement with metakaolin is obtained based on compressive strength test results. The influence of metakaolin on the workability, compressive strength, splitting tensile strength and flexural strength of SCC and its behavior when subjected to elevated temperature was investigated through evaluation against controlled concrete and non-destructive testing. From the test results, it was observed that incorporation of metakaolin at an optimum dosage satisfied all the fresh properties of SCC and improved both the strength and durability performance of SCC compared to controlled concrete.

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Assessment of Rice Husk Ash (RHA) and Calcium Chloride (CaCl2) on Compressive Strength of Concrete Grade 20

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.40.22 ◽

2018 ◽

Vol 40 ◽

pp. 22-29

Author(s):

Joseph A. Ige ◽

Mukaila A. Anifowose ◽

Samson O. Odeyemi ◽

Suleiman A. Adebara ◽

Mufutau O. Oyeleke

Keyword(s):

Compressive Strength ◽

Calcium Chloride ◽

Rice Husk ◽

Rice Husk Ash ◽

Partial Replacement ◽

Hardened Concrete ◽

Conventional Concrete ◽

Compressive Strength Test ◽

Compressive Strength Of Concrete ◽

Strength Result

This research assessed the effect of Nigerian rice husk ash (RHA) and calcium chloride (CaCl2) as partial replacement of cement in concrete grade 20. Rice husk ash (RHA) is obtained by combustion of rice husk in a controlled temperature. The replacement of OPC with rice husk ash (RHA) were 0%, 5%, 10%, 15% and 20%. 1% of Calcium Chloride was blended with OPC/RHA in all the test specimens except from control mix. Concrete cubes of sizes 150mm x 150mm x 150mm were cast and cured in water for 7, 14 and 28 days respectively. Slump test was conducted on fresh concrete while density test and compressive strength test were conducted on hardened concrete. The slump results revealed that the concrete becomes less workable (stiff) as percentage increases. The compressive strength result at 28 days revealed that 5%RHA/1%CaCl2 have the highest strength of 26.82N/mm2 while 20%RHA/1%CaCl2 have the lowest strength (21.48N/mm2). Integration of 5%RHA/1%CaCl2 and 10%RHA/1%CaCl2 as cement replacement will produce a concrete of higher compressive strength compared to conventional concrete in grade 20 concrete.

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Partial Replacement of Ordinary Portland Cement with Sawdust Ash in Concrete

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2019/v32i630036 ◽

2019 ◽

pp. 1-7

Author(s):

L. S. Gwarah ◽

B. M. Akatah ◽

I. Onungwe ◽

P. P. Akpan

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Ordinary Portland Cement ◽

Construction Materials ◽

Partial Replacement ◽

Hardened Concrete ◽

Flow Table ◽

Compressive Strength Test ◽

Increasing Demand ◽

Mixed Concrete

The investigation of sawdust ash (SDA) as a partial replacement for cement in concrete was studied owing to the high cost and increasing demand for cement in a harsh economy and considering the presence of limited construction materials and waste to wealth policy. Ordinary Portland Cement (OPC) was replaced by 0%, 5%, 10%, 15%, 20%, 25% and 30% of SDA. Slump test and consistency test (flow table apparatus test) were conducted on the freshly mixed concrete sample, and compressive strength test was conducted on the hardened concrete cubes of 150mm2, which was cured between 7, 14, 21 and 28 days. The results revealed that the slump decreases as the SDA content increases in percentage, while the consistency of the freshly mixed concrete remarkably moves from high, medium to low as the SDA content increases. The compressive strength of the hardened concrete undergone a decrease in strength, as the partial replacement of OPC with SDA increases. By the results interpretation, it is observed that 5% to 10% SDA when replaced with OPC can still result in the desired strength of concrete.

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Experimental investigation of zeolite and limestone powder on self-compacting concrete strength after early loading

International Journal of Structural Integrity ◽

10.1108/ijsi-05-2018-0031 ◽

2019 ◽

Vol 10 (4) ◽

pp. 515-533

Author(s):

Faeze Nejati ◽

Samira Ahmadi ◽

S.A. Edalatpanah

Keyword(s):

Compressive Strength ◽

High Efficiency ◽

Precast Concrete ◽

Concrete Strength ◽

Construction Materials ◽

Limestone Powder ◽

Self Compacting Concrete ◽

Construction Time ◽

Content Type ◽

Curing Conditions

Purpose Modern construction methods have been developed with the goal of reducing construction time as much as possible, which results in some situations during construction and within the first few days after it, when concrete is subjected to exceptionally high loads. The precast concrete, which is the concrete in very early ages, may result in severe cracks or damages. In conventional construction projects, sometimes working with concrete, which had not reached its ultimate strength, is an unavoidable matter of fact. This paper aims to discuss these issues. Design/methodology/approach Researchers in the field of construction materials have done their best to make some changes in the different parts of the concrete in order to bring about reforms, based on the existing needs, and achieve new quality and primacy from concrete. One kind of concrete, the emergence of which dates back to many years ago, is self-compacting concrete. Thanks to its high efficiency for the parts with complex forms of high-density steel, this kind of concrete suggests new prospects. Findings This study aims at evaluating the effect of early loads on the 28-day compressive strength of concretes with zeolite and limestone powder under different curing conditions (wet or dry). In this regard, two self-compacting concrete mix designs with the same ratio of water to cementations materials and 0.4 percent and 10 percent zeolite have been considered; therefore, concrete cube samples with zeolite and limestone powder in different curing conditions at ages of three, one and seven days under preloading with 80–90 percent of compressive strength are damaged, and after curing in different conditions, their 28-day compressive strength is measured. According to the results, the recovery of the 28-day compressive strength of damaged samples, compared to that of intact samples, is possible in all curing conditions. The experiments that have been performed on concrete samples under dry and wet curing conditions show that the full recovery of compressive strength of damaged samples compared to that of intact ones happened only in preloaded samples at the age of one days, and in other ages (three and seven days) the 28-day strength reduction has occurred in damaged samples compared to the that in intact samples. The results of concrete samples with zeolite and without limestone powder at the age of one day indicate the greatest impact on other samples on the 28-day compressive strength of damaged samples compared to that of intact ones, occurring under dry condition. Originality/value This research analyzed and studied the influence under wet and dry curing conditions and the presence of limestone powder and zeolite fillers in recovering of the 28-day compressive strength of preloaded concrete samples at early stages (one, three and seven days) after the construction of the concrete.

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Use of Thermostone Waste Aggregates for Internal Curing of Reactive Powder Concrete

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/877/1/012043 ◽

2021 ◽

Vol 877 (1) ◽

pp. 012043

Author(s):

Mena A. Gawad ◽

Nada M. Fawzi

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

High Strength ◽

Concrete Surface ◽

Internal Curing ◽

Modulus Of Rupture ◽

Partial Replacement ◽

Reactive Powder Concrete ◽

Curing Methods ◽

Reactive Powder

Abstract The concrete need curing for cement hydration that is a chemical reaction in each step require water supply throughout the time period. The traditional concrete cured by external method that prevents the concrete surface dry so that keeping the concrete mixture wet and warm. The internal curing was adopted in normal and high strength concrete such as reactive powder concrete. In present paper, experimental approach is to study the mechanical properties of reactive powder concrete cured internally with thermostone material. The materials that adopted to evaluate and find out the influences of the internal curing on the mechanical properties of reactive powder concrete is focused with different curing methods such as in water, air and combined water and air. Thermostone aggregate are used as partial sand replacement by volume with different percentages to explore the percentage that effects of the concrete mechanical properties. Test results showed that the best partial replacement by thermostone is 5% gave enhancement and increase in compressive strength and flexural resistance strength (modulus of rupture) and concrete density. Highest increasing of compressive strength is 10.07in case of 5% partial replacement at 90 days. In case of cured the specimens up to 90 days, the increase in modulus of rupture is 4.53%

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The Effect of Styrofoam Artificial Lightweight Aggregate (ALWA) on Compressive Strength of Self Compacting Concrete (SCC)

Civil Engineering Journal ◽

10.28991/cej-03091143 ◽

2018 ◽

Vol 4 (9) ◽

pp. 2111 ◽

Cited By ~ 2

Author(s):

Dhiafah Hera Darayani ◽

Tavio Tavio ◽

I G. P. Raka ◽

Puryanto Puryanto

Keyword(s):

Compressive Strength ◽

Modulus Of Elasticity ◽

Coarse Aggregate ◽

Lightweight Aggregate ◽

Structural Members ◽

Self Compacting Concrete ◽

Conventional Concrete ◽

Concrete Material ◽

Compressive Strength Test ◽

The Impact

Self-compacting concrete (SCC) is a fresh concrete that is able to flow and fill up the formwork by itself without the need of a vibrator to compact it. One of the reasons that causes the damage of a building structure during an earthquake is the heavy weight of its structural members which are from the high density of the material used such concrete material. Lightweight aggregate is one of the solutions to reduce the weight of the structure. Therefore, the SCC using the artificial lightweight aggregate (ALWA) is one of the solutions to reduce the self-weight (dead load) of a structure. This research was conducted to investigate the impact of the use of ALWA in conventional concrete and SCC in terms of its compressive strength and modulus of elasticity. To study the impact of the use of ALWA in SCC, several variation of percentage of ALWA as a substitution to the natural coarse aggregate was examined. The proportions of ALWA as a replacement to the coarse aggregate were 0%, 15%, 50%, and 100%. The test specimens were the cylindrical concrete of 200 mm in height and 100 mm in diameter for both compressive strength and modulus of elasticity tests. The results of the compressive strength test indicated that the higher the percentage of ALWA used in SCC, the lower the compressive strength of the concrete. The addition of ALWA as a substitution to the natural coarse aggregate to conventional concrete and SCC was found optimum at 15% replacement with the compressive strength of conventional concrete and SCC of 21.13 and 28.33 MPa, respectively. Whereas, the modulus of elasticity of the conventional concrete and SCC were found to be 20,843.99 and 23,717.77 MPa, respectively.

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The Influence of Clay Bricks Dust Incorporation on the Self-Curing of Cement Mortar

Journal of Engineering ◽

10.31026/j.eng.2018.12.07 ◽

2018 ◽

Vol 24 (12) ◽

pp. 73-83

Author(s):

Ahmed S. Ali

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Lightweight Aggregate ◽

Modulus Of Rupture ◽

Curing Agent ◽

Curing Conditions ◽

Cement Replacement ◽

Clay Bricks ◽

Cement Additive ◽

Brick Dust

Self- curing is the potential of lightweight aggregate to absorption great amount of water thru mixing which prominently can moves to the paste during hydration process. Self- curing empowers a water to be distributes more evenly act out the cross section. Whereas, the external curing water is only able to penetrate several millimetres into concrete with low water cement ratio. Brick dust accumulates in the demolish site creates serious environmental contamination. This study investigates the effect of brick dust recovered from construction site on the Properties of mortar cured in three curing conditions. Mortar in this study produced using BD as cement additive with (2, 4, 6, and 8) % by weight of cement. BD was used as cement replacement (1, 2, 3, and 4) % by weight of cement. Three curing conditions were experienced in this study to identify whether BD can be used as self- curing agent. Compressive strength, Fresh and hardened density, water absorption, and modulus of rupture were tested. The results of compressive strength and modulus of rupture were decreased when BD used as cement additive and as cement replacement increase. However, they were higher for mortars cured in air conditions than those cured in water and partially water curing. Water absorption, was increased with the increase of (BD) when used as cement additive and replacement. It was indicated BD could be used as self- curing agent and could replace cement at specific ratios which will achieve economical profits and reduce environmental pollution.

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Proportioning Self Compacting Concrete in Hot Weather Utilizing Limestone Powder

10.36937/cebacom.2020.001.002 ◽

2019 ◽

pp. 6-10

Author(s):

Yousif Hummaida Ahmed

Keyword(s):

Compressive Strength ◽

Cement Content ◽

The Self ◽

Limestone Powder ◽

Hardened Concrete ◽

Self Compacting Concrete ◽

Concrete Properties ◽

Slump Flow ◽

Hot Weather ◽

Powder Content

Self-compacting concrete (SCC) is a special type of concrete able to flow and compact under its self-weight. The SCC requires high powder content (mainly of cement) up to 600kg/m3 to achieve its properties. This will be problematic if all cement content in the powder exceeded 400 kg/m3used in hot weather of Sudan. This paper investigates addition of Sudanese limestone powder (LSP) to reduce cement content. The LSP dosages between 20% and 28 % (by cement weight) are used in six mixes having maximum cement content 380kg/m3. Results show that five trial mixes achieved the self-compactibility tested by slump flow, sieve segregation, V-funnel and U-box tests. Compressive strength of these mixes show that the LSP increases strength with dosage. Therefore, further investigations of hardened concrete properties are recommended for the successful mixes to be applied in real projects in the Sudan. Also, it has been found that dry batching and forced-action pan mixers are the most suitable for producing SCC with high homogeneity compared to commercial tilted-drum mixers.

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