Relationship between the Compressive and Tensile Strength of Recycled Concrete

2011 ◽  
Vol 324 ◽  
pp. 348-351 ◽  
Author(s):  
Rouba El Dalati ◽  
Pierre Matar ◽  
Sara Haddad ◽  
Fadi Hage Chehade
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Limited Range ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Compressive Strength ◽  
Concrete Recycling ◽  
The Relationship ◽  
Special Composition

Concrete recycling consists of crushing the concrete provided by demolishing the old constructions, and of using the resulted small pieces as aggregates in the new concrete compositions. The resulted aggregates are called recycled aggregates and the new mix of concrete containing a percentage of recycled aggregates is called recycled concrete. Our previous researches have indicated the optimal percentages of recycled aggregates to be used for different cases of recycled concrete related to the original aggregates nature. All results have shown that the concrete compressive strength is significantly reduced when using recycled aggregates. In order to obtain realistic values of compressive strength, some tests have been carried out by adding water-reducer plasticizer and a specified additional quantity of cement. The results have shown that for a limited range of plasticizer percentage, and a fixed value of additional cement, the compressive strength has reached reasonable value. This paper treats of the effect of using recycled aggregates on the tensile strength of concrete, where concrete results from the special composition defined by our previous work. The aim is to determine the relationship between the compressive and tensile strength of recycled concrete.

scholarly journals Performance of Recycled Aggregate Concrete for M25 Grade Concrete

2019 ◽  
Vol 9 (2) ◽  
pp. 4694-4700
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Inorganic Particles ◽  
Natural Aggregates

Recycled aggregates (RCA) are the aggregates which are made up of crushed, inorganic particles that are obtained from the construction demolition debris. Now a day’s protection of environment is the ultimate challenge to the society. So the usage of RCA’s is the best alternative for the aggregates which are obtained naturally in the construction activity. The scope of using these recycled concrete aggregates is increasing day by day. It reduces the cost effectively as we are using waste concrete as recycled aggregates. The main focus of this paper is to use find the strength qualities of recycled aggregates so as to use it as an alternative for the natural aggregates in high strength concrete for various construction activities. Comparison of workability, compressive strength, tensile strength, elastic modulus and flexural strength of recycled aggregate concrete is made with natural aggregate concrete. Here M25 grade concrete is taken and the natural aggregates were replaced with recycled aggregates in various percentages of 0%, 25%, 50%, 75% and 100%. The mix design for these replacement ratios are done by using code of IS 10262-2009. In order to determine the properties which were mentioned above a total of 60 cubes, 10 beams and 40 cylinders were casted. The compressive strength and tensile strength of RCA concrete have been determined for 7 days and 28 days where as the modulus of elasticity and the flexural strength of RCA concrete are determined after curing for the period of 28 days. The tests done on RCA concrete are compared with concrete which is obtained by natural aggregates As per IS codification the parameters which were determined are reducing moderately as the amount of aggregates which are recycled is being raised

EFFECT OF RECYCLED CONCRETE AGGREGATE QUALITY ON PROPERTIES OF CONCRETE

2020 ◽  
Vol 15 (2) ◽  
pp. 57-69
Author(s):  
Daniel Hatungimana ◽  
Şemsi Yazıcı ◽  
Ali Mardani-Aghabaglou
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Hardened Concrete ◽  
Recycled Concrete Aggregate ◽  
Waste Concrete ◽  
Concrete Production

ABSTRACT The possibility of the use of recycled aggregates from the construction industry in green concrete production is of increasing importance to reduce the negative environmental impact associated with construction and demolition wastes. The objective of this study is to investigate the effect of recycled concrete aggregate (RCA) quality on the properties of hardened concrete properties such as compressive strength, splitting tensile strength, density, water absorption capacity and porosity accessible to water. The RCA used in this study was obtained from the crushing of waste concrete with two different compressive strengths (LRCA obtained from the crushing of waste concrete having compressive strengths below 30 MPa and HRCA obtained from the crushing of waste concrete having compressive strengths above 30 MPa). The natural coarse limestone aggregate was 100% replaced with coarse LRCA and HRCA. As a result of the study, the use of 100% HRCA and %100 LRCA instead of limestone coarse aggregate in the concrete adversely affected its mechanical and physical properties. In addition, HRCA showed better performance in terms of compressive strength, tensile strength, water absorption and porosity compared to the use of LRCA. Furthermore, the percentage of adhered mortar on the surface of LRCA and HRCA was analyzed using a computerized micro tomography device, and it was found that the percentages of attached mortar and aggregates are 61% and 35.5% for LRCA, whilst the attached mortar and aggregate contents for HRCA are 45.9% and 53.7%, respectively.

scholarly journals Evaluation of Concrete Material Properties at Early Age

CivilEng ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 326-350
Author(s):  
Osamah Obayes ◽  
Emad Gad ◽  
Tilak Pokharel ◽  
Jessey Lee ◽  
Kamiran Abdouka
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
Material Properties ◽  
Modulus Of Elasticity ◽  
Inverse Analysis ◽  
Splitting Tensile Strength ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
The Relationship

This article investigates the development of the following material properties of concrete with time: compressive strength, tensile strength, modulus of elasticity, and fracture energy. These properties were determined at seven different hydration ages (18 h, 30 h, 48 h, 72 h, 7 days, 14 days, 28 days) for four pure cement concrete mixes totaling 336 specimens tested throughout the study. Experimental data obtained were used to assess the relationship of the above properties with the concrete compressive strength and how these relationships are affected with age. Further, this study investigates prediction models available in literature and recommendations are made for models that are found suitable for application to early age concrete. Results obtained indicate that the relationship between the splitting tensile strength and concrete compressive strength can be approximated with a power function between 0.7 and 0.8, and this correlation is not affected by age. Fracture energy of the concrete and modulus of elasticity values obtained in this study correlate well with the square root of the compressive strength and it was found that this relationship holds true for all hydration ages investigated in this paper. Inverse analysis on the wedge-splitting test was conducted to determine the direct tensile strength. Values of tensile strength obtained from the inverse analysis have been validated numerically by carrying out finite element analysis on the wedge split, and anchor pull-out tests. The ratio of the tensile strength obtained from the inverse analysis to the splitting tensile strength was found to be in the range of 0.5–0.9 and 0.7 on average.

scholarly journals Experimental Inspection on Shear Capacity in RCC Beams with Partial Replacement of Recycled Coarse Aggregates

2020 ◽  
Vol 9 (2) ◽  
pp. 321-326
Keyword(s):  
Compressive Strength ◽  
Load Ratio ◽  
Shear Capacity ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Age Group ◽  
Shear Span ◽  
Coarse Aggregates ◽  
The Relationship

Demolition waste increasing day by day. The old damaged building materials can be used in present buildings or other construction works. Especially the recycled aggregates are useful to the concrete structures. The experimental studies on the use of recycled coarse aggregate has been going on for many countries. This publication focuses on the relationship between the shear capacity and the flexural cracking load of reinforced recycled concrete beams with stirrups, this experimental Inspection with partial replacement of natural coarse aggregates (NAC) with recycled coarse aggregates (RAC) at different ages as 10, 20 and 30 years in various proportions as 20 per cent, 30 per cent, 40 per cent. For this, M30 grade of concrete is consider. Curing of specimens were done for 7 day and 28 days to conclude the maximum strengths. The obtained results of concrete with partial replacement of recycled aggregates of 10,20and 30 years age group conclude maximum compressive strength of 35.84 N/mm2 at 40% replacement of NCA with RCA of age group (10 years) and 34.12 N/mm2 at 30% replacement of NCA whit RCA of (20 years) age group and 36.14 N/mm2 20% replacement of NCA with RCA of age group (30 years). After the compressive strength, beam specimens were casted for 7day and 28 days. Based on test results of 8 beams, the relationship between the cracking load that causes a beam to crack in the middle of the shear span and the beam's shear capacity is confident. All beams are reinforced in the longitudinal direction only and only tested under two-point loading conditions. The average analytical cracking load ratio is 0.60.the mid-shear span at cracking load (Vcr-a/2) in comparison with the observed shear capacity (Vexp). The analytical cracking load ratio. The analytical cracking’s load was used in this exploration as it is more reliable than the observed cracking load. At mid-span, the shear capacity of most of the beams was shown to be 50%. The average shear capacity ratio to the related test crack load in the center of the shear span 0.43. The analysis showed that cracking loads are strongly related to the shear capacity of the members. This relationship can be used to develop recycled reinforced beam members ' shear design process.

scholarly journals Mechanical Performance of Concrete Made with Recycled Aggregates from Concrete Pavements

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yancong Zhang ◽  
Lingling Gao ◽  
Wei Bian
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Inhibitory Effect ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Concrete Pavements ◽  
Flexural Tensile Strength

This research aims at analysing the mechanical performance of concrete with recycled aggregates from concrete pavements. First, the characteristics of various natural and recycled aggregates used in the concrete were thoroughly analysed. The composition of the recycled aggregates was determined and several physical and chemical tests of the aggregates were performed. In order to evaluate the mechanical performance of recycled concrete, cube compressive strength and flexural tensile strength tests were performed. The effect of recycled aggregates on the strength of recycled concrete is related to the strength of recycled aggregates, the strength of natural aggregates, and the strength of old concrete. The strength of recycled concrete decreases with increasing water-cement ratio. However, due to the water absorption of the recycled aggregate, it has a certain inhibitory effect on the strength reduction. As the replacement rate of recycled aggregates increases, the optimal sand ratio decreases. The sand ratio is controlled between 32% and 38%, which is ideal for recycled concrete. With the increase of fly ash content, the 7 d strength of recycled concrete has decreased to some extent, but the 28 d strength has been slightly improved. In addition, for compressive strength and flexural tensile strength, the optimal content of fly ash is different.

scholarly journals Experimental Study on Recycled Concrete Aggregates with Rice Husk Ash as Partial Cement Replacement

2018 ◽  
Vol 4 (10) ◽  
pp. 2305 ◽  
Author(s):  
Naraindas Bheel ◽  
Shanker Lal Meghwar ◽  
Samiullah Sohu ◽  
Ali Raza Khoso ◽  
Ashok Kumar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Splitting Tensile Strength ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Concrete Aggregates ◽  
Coarse Aggregates

Concrete is highly utilized construction material around the globe and responsible for high depreciation of the raw materials. Consumption of this material in construction industry is arching upward day by day. On the other hand, debris of demolished concrete structures are being dumped as waste. For developing countries such waste is not a good sign and need its proper utilization by recycling it into useful product. In this consequence, this study is an attempt to utilize demolished waste concrete by converting into coarse aggregates. This research was conducted on recycled cement concrete aggregates of demolished structures and Rice Husk Ash (RHA). The purpose of this experimental study is to analyze the mechanical properties of concrete; when cement is partially replaced with RHA and natural aggregates by recycled aggregates (RA). In this study, the cement was replaced by RHA up to 10% by weight of cement. For experimental purpose, total 135 concrete specimens were prepared, cured and tested in Universal Testing Machine (UTM). Finally, laboratory results were compared in terms of compressive and splitting tensile strength made with normal and recycled coarse aggregates. All the specimens were prepared at 1:1.5:3 with 0.50 w/c ratio and tested at 7, 14, 21, 28 and 56 days curing ages. It is observed from experimental analysis that the workability of fresh normal concrete is 7% and 10% greater than recycled aggregates concrete blended with 10% RHA and only recycled aggregates concrete without RHA respectively. The compressive strength increases up to 6%, whilst splitting tensile strength increases 4% at 56 days curing, when the cement is replaced 10% by RHA. It is, further, concluded that with more than 10% RHA replacement with cement, the compressive strength decreases. This study would help the construction experts to use such wasted concrete into useable production of new concrete projects.

scholarly journals Mechanical Behavior of Fine Recycled Concrete Aggregate Concrete with the Mineral Admixtures

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2264
Author(s):  
Minkwan Ju ◽  
Jae-Gwon Jeong ◽  
Martin Palou ◽  
Kyoungsoo Park
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Mechanical Performance ◽  
Total Porosity ◽  
Recycled Concrete ◽  
Mineral Admixtures ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
The Relationship ◽  
Normal Dosage

The paper describes the mechanical behavior of fine recycled concrete aggregate (FRCA) concrete according to the mineral admixtures. Three types of the mineral admixtures, i.e., fly ash (FA), ground-granulated blast-furnace slag (GGBS), and silica fume (SF), are used and the replacement ratios of FRCA are 50% and 100%. The dosages of the admixtures of FA, GGBS, and SF are determined with the normal dosage (30%, 40%, and 5.0%, respectively) based on the ACI committee reports (No. 232, 233, and 234) and half-normal dosage. The mechanical performance is investigated with the compressive and splitting tensile strength, and elastic modulus. Additionally, the total porosity is measured in natural fine aggregate (NFA) and FRCA 100% replaced specimens by mercury intrusion porosimetry (MIP) for investigating the relationship with the compressive strength. Based on the experimental test results, the mineral admixtures improve the mechanical performance of FRCA concrete. The effective dosages of FA, GGBS, and SF for FRCA concrete are investigated according to the replacement ratio of the FRCA. In particular, FRCA 100% replaced concrete may be possible to be used for the structural concrete members with the specific dosage of the mineral admixtures. The prediction of the splitting tensile strength and the elastic modulus by the codes or previous formulas exhibits underestimated and overestimated results, respectively. The relationship between the total porosity and the compressive strength of the FRCA concrete should be modified with more experimental tests.

Recycled Aggregate Concrete Mixture Proportion Method Based on Pulp Content

2014 ◽  
Vol 584-586 ◽  
pp. 1425-1431
Author(s):  
Qing Han ◽  
Zong Ming Jia ◽  
Dong Ye Sun
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Splitting Tensile Strength ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Concrete Mixture ◽  
Concrete Compressive Strength ◽  
Aggregate Concrete ◽  
Proportion Method ◽  
The Relationship

Putting forward a new recycled aggregate concrete mixture proportion method based on the pulp content by researching the effect of pulp content on recycled coarse aggregate physical properties .Research on the cube compressive strength and splitting tensile strength of recycled aggregate concrete by the proposed method and results showed that:The proposed method can reduce the dosage of cement and sand, and increase the recycled aggregate concrete compressive strength and splitting tensile strength ;Establishing the relationship formula between splitting tensile strength and compressive strength of recycled aggregate concrete upon a large number of experimental data.

scholarly journals Experimental Study on Self Compacting Fibrous Concrete Comprising Magnesium Sulphate Solution Treated Recycled Aggregates

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 340
Author(s):  
Parthiban Kathirvel ◽  
Gunasekaran Murali ◽  
Nikolai Ivanovich Vatin ◽  
Sallal R. Abid
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Magnesium Sulphate ◽  
Steel Fibre ◽  
Recycled Concrete ◽  
Sulphate Solution ◽  
Recycled Aggregates ◽  
Partial Replacement ◽  
Concrete Aggregate ◽  
Split Tensile Strength

It appears that the awareness and intentions to use recycled concrete aggregate (RCA) in concrete are expanding over the globe. The production of self-compacting concrete (SCC) using RCA is an emerging field in the construction sector. However, the highly porous and absorptive nature of adhered mortar on RCA’s surface leads to reduced concrete strength, which can be removed with the application of various techniques, such as acid treatment. This study investigated the effect of the partial replacement of silica fume by cement and natural aggregate (NA) by RCA with and without steel fibre. The used RCA was treated with magnesium sulphate solution. It was immersed in solutions with different concentrations of 10%, 15% and 20% and for different periods of 5, 10 and 15 days. Sixteen mixes were prepared, which were divided into six groups with or without 1% of steel fibre content. The fresh properties, compressive strength, split tensile strength and impact resistance were examined. The results revealed that the strengths of the mixes with 20% RCA were marginally better than those of the control mixes. The compressive strength and split tensile strength were reduced by 34% and 35% at 60% RCA content, respectively, as compared to the control mixes.

scholarly journals Analysis of High Strength Concrete processed from Recycled Concrete Aggregates

2021 ◽  
Vol 9 (12) ◽  
pp. 1757-1763
Author(s):  
Shanu Sharma
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Strain Curve ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Stress Strain Curve ◽  
Stress Strain

Abstract: As everyone is aware of the fact that Natural Coarse Aggregate (NCA) is the main constituent of traditional concrete mixes. Whenever an existing concrete structure is demolished, it produces smashed concrete waste in the large amount. Concrete waste give rise to negative effects on the environment. To evade the environmental pollution and mark effective reuse of the concrete waste as Recycled Aggregates in the place of NCA. This operative initiative provides an opportunity to reduce air pollution and soil exploitation to some extent. Such concrete is sustainable in nature and also eco-friendly to the environment. Also, such waste material will lower the usage of naturally occurring stone to produce NCA and thus various natural energy resources will be safeguarded. This study covers the suitability norms for a material to be used for Recycled Aggregate. In this study the natural aggregate is replaced with recycled aggregate in the different percentages (0%, 25%, 50%). When percentage of recycled aggregate mixed in the fixed proportion as percentage replacement to natural aggregates, it imparts improvement in the property of fresh as well as hardened concrete like, compressive strength & split tensile strength. Laboratory results of this research indicates that the value of compressive strength, tensile strength stress-strain curve & NDT of these mixes drives on decreasing, but at the 25% replacement level, it achieves target mean strength. Hence, for the fundamental concrete mix Natural Coarse Aggregate can be efficiently replaced by the Recycled Aggregate to the range of 25%. Keywords: Concrete, Recycled aggregate, Natural Coarse Aggregate (NCA), Compressive Strength, Tensile strength, , NDT, Stress-Strain Curve

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