The Aggregate’s Influences on Properties of Porous Pervious Concrete Made of Recycled Aggregates

2014 ◽  
Vol 584-586 ◽  
pp. 1271-1275
Author(s):  
Ping Gong ◽  
Wen Liang Zhang

In this study,different particle size’s aggregates ,different aggregate correction coefficients and different sand ratio were selected to study the aggregate’s influences on properties of porous pervious concrete made of recycled aggregates.The results shows that the 28-day compressive strength of concrete with single particle size is lower than those with two kinds of particle mixing ,as for the permeability coefficient, the former is much higher than the latter .With the aggregate correction coefficient’s increase,the 28-day compressive strengths of concrete increases first and then decreases, the permeability coefficient increases . The 28-day compressive strengths of concrete increases with the increase of the sand ratio. the permeability coefficient increases first ,decreases then.

2014 ◽  
Vol 919-921 ◽  
pp. 1934-1938
Author(s):  
Ping Gong ◽  
Yu Zhou

In this study,silica fume and fly ash were used to replace part of cement, the 28-days compressive strength and the permeability coefficient were tested to study influences of mineral admixture on properties of porous pervious concrete made of recycled aggregates.The results show the best effect is to multiplexed mix with fly ash and silica fume, the 28-day compressive strengths of concrete is higher than those single mixed or doesn’t mix any mineral admixture.


2021 ◽  
Vol 11 (2) ◽  
pp. 485
Author(s):  
Amirreza Kandiri ◽  
Farid Sartipi ◽  
Mahdi Kioumarsi

Using recycled aggregate in concrete is one of the best ways to reduce construction pollution and prevent the exploitation of natural resources to provide the needed aggregate. However, recycled aggregates affect the mechanical properties of concrete, but the existing information on the subject is less than what the industry needs. Compressive strength, on the other hand, is the most important mechanical property of concrete. Therefore, having predictive models to provide the required information can be helpful to convince the industry to increase the use of recycled aggregate in concrete. In this research, three different optimization algorithms including genetic algorithm (GA), salp swarm algorithm (SSA), and grasshopper optimization algorithm (GOA) are employed to be hybridized with artificial neural network (ANN) separately to predict the compressive strength of concrete containing recycled aggregate, and a M5P tree model is used to test the efficiency of the ANNs. The results of this study show the superior efficiency of the modified ANN with SSA when compared to other models. However, the statistical indicators of the hybrid ANNs with SSA, GA, and GOA are so close to each other.


2020 ◽  
Vol 846 ◽  
pp. 207-212
Author(s):  
Ming Gin Lee ◽  
Yung Chih Wang ◽  
Wan Xuan Xiao ◽  
Ming Ju Lee ◽  
Tuz Yuan Huang

This study was conducted to assess the effect of CO2 curing on the compressive strength of high strength pervious concrete. The factors studied to evaluate compressive strength of concrete on CO2 curing pressure, curing time, and age of specimen at testing. Three Aggregate sizes, three CO2 curing pressures, three CO2 curing time, and three testing ages were used in this investigation. The research tried to produce a high strength pervious concrete and use carbon dioxide for curing to find out whether it could enhance the compressive strength. The results show that the compressive strength of the control group increases rapidly and its 90-day compressive strength closed to 60 MPa. The 1-day compressive strength has a major impact after CO2 curing and their strength decreased by about 0% to 50% as compared to the control group. However, it is observed that there is only slight difference in relationship between modulus of elasticity and compressive strength obtained from 100 by 200mm cylinders with CO2 curing.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4631 ◽  
Author(s):  
Jingwei Ying ◽  
Zewen Han ◽  
Luming Shen ◽  
Wengui Li

Parent concrete coming from a wide range of sources can result in considerable differences in the properties of recycled coarse aggregate (RCA). In this study, the RCAs were obtained by crushing the parent concrete with water-to-cement ratios (W/Cparent) of 0.4, 0.5 and 0.6, respectively, and were strengthened by carbonation and nano-silica slurry wrapping methods. It was found that when W/Cparen was 0.3, 0.4 and 0.5, respectively, compared with the mortar in the untreated RCA, the capillary porosity of the mortar in the carbonated RCA decreased by 19%, 16% and 30%, respectively; the compressive strength of concrete containing the carbonated RCA increased by 13%, 11% and 13%, respectively; the chloride diffusion coefficient of RAC (DRAC) containing the nano-SiO2 slurry-treated RCA decreased by 17%, 16% and 11%; and that of RAC containing the carbonated RCA decreased by 21%, 25% and 26%, respectively. Regardless of being strengthened or not, both DRAC and porosity of old mortar in RCAs increased with increasing W/Cparent. For different types of RCAs, DRAC increased obviously with increasing water absorption of RCA. Finally, a theoretical model of DRAC considering the water absorption of RCA was established and verified by experiments, which can be used to predict the DRAC under the influence of different factors, especially the water absorption of RCA.


2019 ◽  
Vol 12 (1) ◽  
pp. 101-121 ◽  
Author(s):  
S. E. PILS ◽  
P. OLIVEIRA ◽  
F. REGOSO ◽  
V. A. PAULON ◽  
M. F. COSTELLA

Abstract The use of pervious concrete to minimize the effects caused by the impermeability of the soil as a result of increasing urbanization is an alternative that still requires further studies regarding its design and implementation. From this perspective, this paper presents a study of the characteristics of pervious concrete, including its tensile strength, compressive strength, flexural strength and the permeability coefficient, through the development of various mixtures to adjust the characteristics of the local aggregates. Eight mixtures were studied based on a reference mixture, five of which were related to the pervious concrete with the addition of finer aggregates than the reference mixture without these aggregates. Subsequently, three mixtures were studied with the inclusion of polypropylene fibers in order to analyze the effects of the addition of fibers on the properties of the pervious concrete. It is concluded that the presence of fibers changed the characteristics of the concrete, increasing its strengths while achieving a good permeability in its mixtures. An improvement in the flexural strength of the pervious concrete was observed, which is the main property to be considered for its use in pavements, without harming the permeability, which raises the possibility for its application.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1894-1898
Author(s):  
Run Dong Gao ◽  
Qing Feng Xu ◽  
Xiang Min Li ◽  
Min Shan Du

Performance tests are conducted on pervious concrete mixed with Polypropylene Split Fiber (PPSF), in which basic indexes such as compressive strength, splitting strength, flexural strength, porosity, permeability coefficient are measured. Results indicate: mixed with certain amount of PPSF in ordinary pervious concrete is feasible, and during mixing PPSF is split into uniformly distributed monofilament fiber without occurrence of agglomeration or rustiness; incorporating 3kg PPSF in 1m3 pervious concrete is proper, under which compared with the ordinary pervious concrete, both porosity and permeability coefficient are decreased, but application requirements are still met, while strength is increased obviously; the pervious concrete mixed with PPSF can be used in ordinary light traffic pavements.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 321 ◽  
Author(s):  
Haitang Zhu ◽  
Chengcheng Wen ◽  
Zhanqiao Wang ◽  
Lan Li

Pervious concrete is considered to be porous concrete because of its pore structure and excellent permeability. In general, larger porosity will increase the permeability coefficient, but will significantly decrease the compressive strength. The effects of water-cement ratio, fiber types, and fiber content on the permeability coefficient, porosity, compressive strength, and flexural strength were investigated. The pore tortuosity of the pervious concrete was determined by volumetric analysis and two-dimensional cross-sectional image analysis. The concept and calculation method of porosity tortuosity were further proposed. Results show that the permeability coefficient of the pervious concrete is the most suitable with a water-cement ratio of 0.30; the water permeability of the pervious concrete is influenced by fiber diameter. The permeability coefficient of pervious concrete with polypropylene thick fiber (PPTF) is greater than that with copper coated steel fiber (CCF) and the polypropylene fiber (PPF). The permeability coefficient is related to tortuosity and porosity, but when porosity is the same, the permeability coefficient may be different. Finally, general relations between the permeability coefficient and porosity tortuosity are constructed.


Sign in / Sign up

Export Citation Format

Share Document