scholarly journals Mechanical Properties of Recycled Concrete in Marine Environment

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jianxiu Wang ◽  
Tianrong Huang ◽  
Xiaotian Liu ◽  
Pengcheng Wu ◽  
Zhiying Guo

Experimental work was carried out to develop information about mechanical properties of recycled concrete (RC) in marine environment. By using the seawater and dry-wet circulation to simulate the marine environment, specimens of RC were tested with different replacement percentages of 0%, 30%, and 60% after immersing in seawater for 4, 8, 12, and 16 months, respectively. Based on the analysis of the stress-strain curves (SSCs) and compressive strength, it is revealed that RC’ peak value and elastic modulus decreased with the increase of replacement percentage and corroding time in marine environment. And the failure of recycled concrete was speeded up with more obvious cracks and larger angles of 65° to 85° in the surface when compared with normal concrete. Finally, the grey model (GM) with equal time intervals was constructed to investigate the law of compressive strength of recycled concrete in marine environment, and it is found that the GM is accurate and feasible for the prediction of RC compressive strength in marine environment.

2020 ◽  
Vol 841 ◽  
pp. 138-143
Author(s):  
Sallehan Ismail ◽  
Mahyuddin Ramli

This study also investigates the effectiveness of multiple surface modification of recycled concrete aggregate (RCA) with respect to mechanical properties of the resultant recycled aggregate concrete (RAC) when exposed to various curing conditions, namely, normal water (Nw) and seawater (Sw). The properties included compressive and flexural strength and impact resistance. Findings show that effect inclusion of the treated coarse RCA is significant in enhancing the mechanical properties of RAC. The exposure to Sw appears to affect the degradation of the compressive strength of RAC remarkably in a marine environment. In this case, however, using of treated RCA is found beneficial in decreasing the deterioration in the compressive strength of RAC.


2012 ◽  
Vol 166-169 ◽  
pp. 3323-3328
Author(s):  
Ling Jun Xie ◽  
Ai Liang Zhai ◽  
Chun He Wang ◽  
Chang Liang Ji ◽  
Shu Jian Chen

By experimental, study on the elastic modulus including the failure modes of Recycled Concrete made of Brick and Tile with the splitting tensile strength and the compressive strength, And the relational formula between the splitting tensile strength and the compressive strength was summarized from the results.


2010 ◽  
Vol 168-170 ◽  
pp. 1869-1874
Author(s):  
Meng Fu Wang ◽  
Xing Yu Song

The relationships between the mechanical properties of modified concrete and the composition of latex blend were studied. Influence of steel fiber and polypropylene fiber on performance of modified concrete was analyzed on that basis. The results indicate that the contradiction between the strength and the damping property of normal concrete will be relieved to some degree by controlling the proportion of latex blend. The adding of fiber can modify the damping property of concrete, while it has a little effects on the compressive strength and elastic modulus of concrete.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.


2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.


2014 ◽  
Vol 894 ◽  
pp. 45-49 ◽  
Author(s):  
Luisa Pani ◽  
Lorena Francesconi

In this paper an experimental program has been carried out in order to compare compressive strength fcand elastic static modulus Ecof recycled concrete with ultrasonic waves velocity Vp, to establish the possibility of employing nondestructive ultrasonic tests to qualify recycled concrete. 9 mix of concrete with different substitution percentage of recycled aggregates instead of natural ones and 27 cylindrical samples have been made. At first ultrasonic tests have been carried out on cylindrical samples, later elastic static modulus Ecand compressive strength fchave been experimentally evaluated. The dynamic elastic modulus Edhas been determined in function of ultrasonic wave velocity Vp; furthermore the correlations among Ed, Ec, fce Vphave been determined. It has been demonstrated that ultrasonic tests are suitable for evaluating different deformative and resisting concrete performances even when variations are small.


2011 ◽  
Vol 418-420 ◽  
pp. 406-410
Author(s):  
Jun Liu ◽  
Yao Li ◽  
Dan Dan Hong ◽  
Yu Liu

Abstract. Recycled aggregate—rural building material wastes pretreated by cement mortar—are applied into concrete with different replacement rates: 0, 25%, 50%, 75%, and 100%. Results from measurements of compressive strength, cleavage tensile strength, mass loss after fast freeze-thaw cycles, and compressive strength loss indicate that a different recycled aggregate replacement rate certainly influences concrete mechanical properties and frost resistance. Recycled aggregate replacement rates less than 75% performs better than common concrete. Data from the 100% replacement rate is worse than that of rates less than 75% but still satisfy the general demands of GB standard on C30 concrete.


2007 ◽  
Vol 330-332 ◽  
pp. 907-910
Author(s):  
Fa Ming Zhang ◽  
Jiang Chang ◽  
Jian Xi Lu ◽  
Kai Li Lin

Attempt to increase the mechanical properties of porous bioceramics, a dense/porous structured β-TCP bioceramics that mimic the characteristics of nature bone were fabricated. Experimental results show that the dense/porous structured β-TCP bioceramics demonstrated excellent mechanical properties with compressive strength up to 74 MPa and elastic modulus up to 960 MPa, which could be tailored by the dense/porous cross-sectional area ratio obeying the rule of exponential growth. The interface between the dense and porous bioceramics is connected compactly and tightly with some micropores distributed in the matrix of both porous and dense counterparts. The dense/porous structure of β-TCP bioceramics may provide an effective way to increase the mechanical properties of porous bioceramics for bone regeneration at weight bearing sites.


2011 ◽  
Vol 399-401 ◽  
pp. 2155-2159
Author(s):  
Qing Sheng Liu ◽  
Hui Fang

Based on the service ambient with aluminium electrolysis condition, the evolution of compressive strength, elastic modulus and stress-strain curve of carbon cathode samples under various conditions are investigated by experimental simulation method; the deterioration mechanism of the mechanical of carbon cathode is also studied. Results show that different carbon cathode materials and ambient conditions have great influence on strength and elastic modulus of carbon cthode. The mechanical properties such as compressive strength and elastic modulus of carbon catodes can be degraded by the erosion of sodium and molten salt during aluminium electrolysis, that has been confirmation by the SEM and XRD analysis.


2021 ◽  
Vol 28 (1) ◽  
pp. 516-527
Author(s):  
Jiangwei Bian ◽  
Wenbing Zhang ◽  
Zhenzhong Shen ◽  
Song Li ◽  
Zhanglan Chen

Abstract The most significant difference between recycled and natural concretes lies in aggregates. The performance of recycled coarse aggregates directly affects the characteristics of recycled concrete. Therefore, an in-depth study of aggregate characteristics is of great significance for improving the quality of recycled concrete. Based on the coarse aggregate content, maximum aggregate size, and aggregate shape, this study uses experiments, theoretical analysis, and numerical simulation to reveal the impact of aggregate characteristics on the mechanical properties of recycled concrete. In this study, we selected the coarse aggregate content, maximum aggregate size, and the aggregate shape as design variables to establish the regression equations of the peak stress and elastic modulus of recycled concrete using the response surface methodology. The results showed that the peak stress and elastic modulus of recycled concrete reach the best when the coarse aggregate content is 45%, the maximum coarse aggregate size is 16 mm, and the regular round coarse aggregates occupy 75%. Such results provide a theoretical basis for the resource utilization and engineering design of recycled aggregates.


Sign in / Sign up

Export Citation Format

Share Document