Analytical model for compressive strength, elastic modulus and peak strain of structural lightweight aggregate concrete

2012 ◽  
Vol 36 ◽  
pp. 1036-1043 ◽  
Author(s):  
H.Z. Cui ◽  
Tommy Yiu Lo ◽  
Shazim Ali Memon ◽  
F. Xing ◽  
X. Shi
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Analytical Model ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Peak Strain ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

scholarly journals Evaluation of Stress–Strain Behavior of Self-Compacting Rubber Lightweight Aggregate Concrete under Uniaxial Compression Loading

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4064 ◽  
Author(s):  
Jing Lv ◽  
Tianhua Zhou ◽  
Qiang Du ◽  
Kunlun Li ◽  
Kai Sun
Keyword(s):  
Compressive Strength ◽  
Failure Modes ◽  
Experimental Studies ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Peak Strain ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Rubber Particles ◽  
Strain Relationship

The recycling of waste tires in lightweight aggregate concrete (LC) would achieve huge environmental and societal benefits, but the effects of rubber particles on the partial properties of LC are not clear (e.g., the stress–strain relationship). In this paper, uniaxial compressive experiments were conducted to evaluate the stress–strain relationship of self-compacting rubber lightweight aggregate concrete (SCRLC). Rubber particles were used to replace sand by volume, and substitution percentages of 0%, 10%, 20%, 30%, 40%, and 50% were set as influence factors. Experimental results indicate that with increased rubber particles substitution percentage, the cubic compressive strength and axial compressive strength of SCRLC decreased, while the failure modes of SCRLC prism specimens gradually changed from brittle to ductile failure. As the rubber particles substitution percentage increased from 0% to 50%, the peak strain of SCRLC increased whereas peak stress, elastic modulus, and peak secant modulus of SCRLC deceased, the descending stage of stress–strain curves became softer. The rubber particles substitution percentage of 30% was the critical point at which an obvious change in the properties of SCRLC occurred. Based on the data collected from experimental studies, a predictive model for SCRLC was established and a further prediction of the SCRLC stress–strain relationship was given.

scholarly journals The Effects of Additives to Lightweight Aggregate on the Mechanical Properties of Structural Lightweight Aggregate Concrete

2021 ◽  
Vol 31 (1) ◽  
pp. 139-160
Author(s):  
Mehdi Khoshvatan ◽  
Majid Pouraminia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Specific Gravity ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Lightweight Aggregates ◽  
Structural Concrete ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

Abstract 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 kg m 3 while increasing the amount of cement from 300 to 400 kg m 3 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 rate of tensile strength to 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.

The Effects of Cement Content, Sand Percentage and Fly Ash Dosage on Lightweight Aggregate Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 282-287
Author(s):  
Liu Wei ◽  
Feng Xing ◽  
Lu Han
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Class ◽  
Cement Content ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Ongoing Research ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

The paper is one part of ongoing research on structural lightweight aggregate concrete. Lightweight aggregate concrete with compressive strength class of CL40 and slump of 160-200 mm were studied. The influences of the cement content, sand percentage and fly ash dosage on properties of fresh and hardened LWAC, such as fresh density, workability and compressive strength were investigated.

scholarly journals Mechanical Properties and Conversion Relations of Strength Indexes for Stone/Sand-Lightweight Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xianggang Zhang ◽  
Dapeng Deng ◽  
Jianhui Yang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Poisson’S Ratio ◽  
Lightweight Aggregate ◽  
Poisson's Ratio ◽  
Lightweight Aggregate Concrete ◽  
Replacement Rate ◽  
River Sand ◽  
Aggregate Concrete ◽  
Axial Compressive Strength

This is a study of the basic mechanical properties of specified density shale aggregate concrete, which is based on different replacement rates in stone-lightweight aggregate concrete (stone-LAC) and sand-lightweight aggregate concrete (sand-LAC). They were prepared by replacing the ceramsite and pottery sand with stone and river sand, respectively. Many tests were performed regarding the basic mechanical property indexes, including tests of cube compressive strength, axial compressive strength, splitting tensile strength, flexural strength, elastic modulus and Poisson’s ratio. The failure modes of specified density shale aggregate concrete were obtained. The effects of replacement rates on the mechanical property indexes of specified density shale aggregate concrete were analyzed. Calculation models were implemented for elastic modulus, for the conversion relations between the axial compressive strength and the cube compressive strength, and for the relations between the tension-compression ratio and Poisson’s ratio. It was shown that when the replacement rate of stone or river sand increased from 0% to 100%, the cube compressive strength of stone-LAC and sand-LAC increased, respectively, by 55% and 25%, the axial compressive strength increased, respectively, by 91% and 72%, splitting tensile strength increased, respectively, by 99% and 44%, and the flexural strength increased, respectively, by 46% and 26%. Similarly, the elastic modulus of stone-LAC and sand-LAC increased, respectively, by 16% and 30%. However, Poisson’s ratio for stone-LAC decreased first and then increased, eventually increased by 11%; Poisson’s ratio for sand-LAC only reduced gradually, eventually reduced by 67%. After introducing the influence parameter for the replacement rate, the established calculation models become simple and practical, and the calculation accuracies are favorable.

Compressive Strength Variations in Lightweight Aggregate Concrete Samples Affected by Segregation Caused by Excessive Vibration

2019 ◽  
Vol 821 ◽  
pp. 493-499 ◽  
Author(s):  
Afonso Miguel Solak ◽  
Antonio José Tenza-Abril
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniform Distribution ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Global Properties ◽  
Concrete Failure ◽  
Good Homogeneity ◽  
Cylindrical Samples

Lightweight aggregates used in lightweight aggregate concrete (LWAC) exert an important influence on the compressive strength and elastic modulus of concrete. A good homogeneity of the material is essential in this type of concrete once a non-uniform distribution of aggregates in the mixture may strongly affect the concrete global properties, which are commonly considered as homogenous values for design purposes. LWAC, due to density differences among its components, are susceptive to segregation. The separation of the aggregates from the rest of the mixture increases the risk of cracking and areas where segregation or insufficient compaction occur are mostly the areas where the concrete failure begins. The aim of this study is analysing possible variations caused by segregation on compressive strength (fc) along the height of cylindrical samples, comparing results of four sections extracted from samples segregated intentionally.

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