Behavior of structural lightweight concrete produced with expanded clay aggregate and after exposure to high temperatures (original) (raw)
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2017
In this study, the influence of elevated temperature on the physical and mechanical properties of concrete produced by expanded clay aggregate and calcium aluminate cement (CAC) was investigated. For this purpose three different mixture were prepared. First mixture was produced by using ordinary Portland Cement (OPC) and natural aggregate. Second mixture was prepared by OPC and expanded clay aggregate. Third mixture was produced by using CAC and expanded clay aggregate. The water-cement (w/c) ratio used in the mixtures was determined as 0.50. The concrete specimens were heated in an electric furnace up to 200, 400, 600, 800 and 1000 °C and kept at these temperatures for one hour. Two cooling regimes (slow and fast) were used. The residual compressive strength, weight loss, water absorption and porosity ratio and ultrasonic wave velocity values of the specimens were measured. The test results show that exposing to elevated temperatures adversely affected the mechanical and physical p...
Mechanical Properties of Light Weight Concrete using Lightweight Expanded Clay Aggregate
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022
This research investigates the impact of partially substituting coarse aggregate with light weight coarse material (LECA). In numerous aspects, LECA mirrors the properties of coarse aggregate. Because self-weight accounts for a major amount of the total load applied to the structure, LECA is utilized in concrete to lower the need for coarse aggregate and in the design of concrete buildings. This is crucial in circumstances like poor soils and tall constructions. It also offers significant advantages in terms of lowering concrete density, which improves labour efficiency. Lightweight concrete has a lower density than standard concrete and provides better thermal insulation. The main purpose of this study is to examine the weight and strength characteristics of concrete, such as cube compressive strength, split tensile strength cylinders, and flexural strength of light weight concrete versus conventional concrete by substituting LECA for natural aggregates by 25%, 50%, 75%, and 100%, respectively. For far over two millennia, lightweight aggregate has been used successfully.
CVR Journal of Science & Technology, 2019
Lightweight concrete can be produced by replacing the normal aggregate with lightweight aggregate either partially or fully, depending upon the requirements of density and strength. The present study covers the influence of different aggregate curing conditions and admixtures on the strength of lightweight expanded clay aggregate concrete under normal curing and vacuum curing with and without addition of silica fume. The grade of the concrete is M40. The lightweight aggregate used is LECA, an expanded clay aggregate. Investigations were carried out up to a replacement of 50% of coarse aggregate. The workability and strength at different ages are presented.
2017
Concrete is a building material commonly used in the construction structures. There are many reasons why concrete is preferred. One of these reasons is fire resistance of concrete. Concrete is not a combustible material, but it behaves differently under high temperature. Aggregates constitute an important part of concrete volume. Differences in aggregate properties significantly affect the performance of the concrete during heating. Differences in these properties also cause cracks and breakages in parts of the concrete and significant losses in adherence. When we look at these effects, we have seen that high temperature creates a threatening environment for concrete. Therefore, it is necessary to investigate the behavior of the concrete caused by the high temperature. In this study, we investigated the effect of high temperature on the compressive strength of concrete specimens prepared using different aggregate types. For this purpose, 10 × 10 × 10 cm and 15 × 15 × 15 cm cube samp...
SCIENDO, 2021
In the paper, the effects of different percentages of additives (perlite, LECA, pumice) on the mechanical properties of structural lightweight aggregate concrete were tested and evaluated. For the research, 14 mixing designs with different amounts of aggregate, water, and cement were made. Experimental results showed that the specific gravity of lightweight structural concrete made from a mixture of LECA, pumice, and perlite aggregates could be 25-30% lighter than conventional concrete. Lightweight structural concrete with a standard specific gravity can be achieved by using a combination of light LECA with perlite lightweight aggregates (LA) and pumice with perlite in concrete. The results indicated that LECA lightweight aggregates show more effective behavior in the concrete sample. Also, the amount of cement had a direct effect on increasing the strength regardless of the composition of LAs. The amount of cement causes compressive strength to increase. Furthermore, the stability of different experimental models increased from 156 to 345 3 kg m while increasing the amount of cement from 300 to 400 3 kg m in the mixing designs of LECA and perlite for W/C ratios of 0.3, 0.35, and 0.4. For a fixed amount of cement equal to 300 kg, the compressive strength is reduced by 4% by changing the water to cement ratio from 0.5 to 0.4. The compression ratios of strength for 7 to 28 days obtained in this study for lightweight concrete were between 0.67-0.8. Based on the 2 Corresponding 140 Mehdi KHOSHVATAN, Majid POURAMINIAN rate of tensile strength to the compressive strength of ordinary concretes, which is approximately 10, this ratio is about 13.5 to-17.8 in selected and optimal lightweight concretes in this research, which can be considered good indirect tensile strength for structural lightweight concretes.
STUDY ON EFFECTS OF LIGHT WEIGHT AGGREGATES ON COMPRESSIVE AND FLEXURAL STRENGTH OF CONCRETE
The present day world is witnessing construction of very challenging and difficult civil engineering structures. In this study comparison has been made between plain cement concrete and light weight concrete having different proportion of aggregates and admixtures. i.e., Expanded Clay Aggregates: 0%, 25%, 50%, 75% and 100% with coarse aggregate, silica fumes 10% and PVA(Poly Vinyl Alcohol) 1.6% of constant replacement with cement and water respectively. It helps to increase the volume of concrete and hence reduce the weight. In Design of concrete structures, light weight concrete plays a prominent role in reducing the density and to increase the thermal insulation. These may relate of both structural integrity & serviceability. More environmental and economical benefits can be achieved if waste materials can be used to replace the fine light weight aggregate.
Development of Innovative Structural Light Weight Concrete by using Expanded Clay Aggregates
Lightweight concrete can be produced by replacing the normal aggregate with lightweight aggregate, either partially or fully, depending upon the requirements of density and strength. The present study covers the use of Expanded Clay Aggregate (LECA) as lightweight aggregate in concretes containing micro silica as a supplementary cementations material. The main aim of this project is to develop the Lightweight concrete for structural use. The different mixes were designed by using the efficiency of micro silica with the different percentages of light weight aggregate LECA and Sintagg. The resulting concretes were seen to have densities varying from 900 to 1860 kg/m3, with the corresponding compressive strengths varying from 5 to 35 MPa which leads in reduction of dead load, faster building rates and lower haulage and handling costs to pull off economy.
Experimental Study on Light Weight Concrete by Using Light Expanded Clay Aggregate (LECA
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022
This study examined the structural behavior of Lightweight concrete (LWAC) using lightweight aggregates (Light expanded clay aggregates LECA) and normal weight aggregates, aims to investigate on concrete mix M25 by the effect of partially and fully replacement of the coarse aggregate by LECA with various percentage such as 20%, 40%, 60%, 80% and 100%. Analysis of this concrete was done in fresh state as well in hardened state to evaluate mechanical properties of concrete. This paper concentrated on performance parameters such as compressive strength, splitting tensile strength of the light weight concrete using LECA. The Lightweight concrete density varies from 40%-100% replacement of LECA such as 1996kg/m3-1597kg/m3. It reduces the weight of concrete and cost of concrete by reducing the aggregate cost and produces economical system.
Mechanical and physical properties of heavyweight concrete
2020
Heavyweight concretes with compressive strength exceeding 45 MPa and bulk density ranging between 3400 and 3500 kg.m-3 were prepared using two types of high-density aggregates (barite and magnetite), Portland cement and supplementary cementitious materials. The composition of the binder was optimized through hydration. The concrete design was based, not only on a general rule of mix proportion calculation but has considered the presence of radioisotopes analysed by Nuclear Activation Analysis (NAA). After a short period of volume expansion (up to 4 hours), a slight shrinkage (max. 0.3°/°°) has been observed. In addition, thermophysical properties (thermal conductivity, volumetric specific heat, thermal diffusivity) and other properties were determined. The results showed that aggregate content and not binder is the main factor influencing the engineering properties of heavyweight concretes.
Journal of Cleaner Production, 2015
In this paper the main mechanical properties of concrete produced with recycled aggregates obtained from crushing both structural and non-structural lightweight concrete are characterized. Various concrete mixes with replacement ratios of 20%, 50% and 100% of two types of coarse lightweight aggregates (LWA) by recycled lightweight concrete aggregates (RLCA) were studied in terms of their compressive strength, tensile strength, modulus of elasticity and abrasion resistance. Generally the experimental results show that all the studied properties are improved with the introduction of RLCA. In particular, concrete with RLCA has higher structural efficiency than the reference concrete, with LWA alone. It is thus concluded that more cost-effective structural lightweight concrete (LWC) can be produced with the introduction of RLCA. Moreover, it is shown that the RLCA obtained from non-structural lightweight concrete can be used to produce structural LWC. There is a slight reduction of the concrete's mechanical properties when the stronger LWA is replaced with the more porous RLCA obtained from non-structural lightweight concrete.