Pervious concrete

About: Pervious concrete is a research topic. Over the lifetime, 2920 publications have been published within this topic receiving 27720 citations. The topic is also known as: porous concrete & permeable concrete.

Specialadmixture for pervious concrete and application ofspecialadmixture

Abstract: The invention discloses a specialadmixture for pervious concrete and application of the specialadmixture. Thespecial admixture comprises the following materials in weight percent: 5 to 15 percent (solid content) of a water reducing agent; 0.1 to 1 percent of a retarder; 0.1 to 1 percent of a thickener; 15 to 25 percent of an early strength agent; 25 to 50 percent of a water-repellent agent; 25 to 50 percent of rubber powder. The admixture overcomes the problem that the existing pervious concrete is not easy to transport bya tanker, and ensures that the phenomenon of blocking cannot occur when the pervious concrete is put into a tanker after the admixture is used, has excellent service behavior after the pervious concrete is discharged from the tanker, and has excellent cohesiveness, without phenomena of bottom sealing and hole blocking.

Laboratory study of porous concrete for its use as top-layer of concrete pavements

Abstract: Included in the project 'Optimization of Surface Characteristics of Concrete Roads in Accordance with Environmental Acceptance and Traffic Safety' is a lab program being carried out by various European institutes to study the composition and characteristics of porous concrete for use as top-layer of concrete pavements. The main aim of this work is to optimize the composition of porous concrete with respect to strength, acoustic properties, drainage, durability, and costs comparable to porous asphalt. This latter material is now widely used in different European countries due to its noise reducing and drainage properties. These 2 aspects are now considered to be very important because of environmental impact and safety matters. To date, results obtained have given very useful information on the relationship between porous concrete composition and characteristics. These relationships were actually used to define the most appropriate mixtures to be used in specific projects. This paper describes the testing program carried out, as well as the results obtained so far and the corresponding practical consequences.

Compressive Strength of Pervious Concrete Pavements

Abstract: The pervious concrete system and its corresponding strength are as important as its permeability characteristics. The strength of the system not only relies on the compressive strength of the pervious concrete but also on the strength of the soil beneath the support. Previous studies indicate that pervious concrete has lower compressive strength capabilities than conventional concrete and will only support light traffic loadings. This project conducted experimental studies on the compressive strength of pervious concrete as it related to water-cement ratio, aggregate-cement ratio, aggregate size, and compaction. Since voids are supposed to reduce the strength of concrete, the goal is to find a balance between water, aggregate, and cement in order to increase strength and permeability, two characteristics which tend to counteract each other. Also important is appropriate traffic loads and volumes so that pervious concrete is able to maintain structural integrity. This research confirms that pervious concrete does in fact proved a lower compressive strength than that of conventional concrete; compressive strengths in acceptable mixtures only reached about 1700 psi. Analysis of traffic loadings reinforce the fact that pervious concrete cannot be subjected to large numbers of heavy vehicle loadings over time, although pervious concrete would be able to sustain low volumes of heavy loads if designed properly. In all cases, high permeability rates were achieved regardless of the compressive strength.

A Study on Mechanical Properties of Porous Concrete Using Cementless Binder

Abstract: This study evaluated the mechanical characteristics and durability of porous concrete produced with a cementless binder based on ground granulated blast furnace slag (BFS), fly ash (FA) and flue gas desulfurization gypsum (CP). As a result, the void ratio was increased slightly from the target void ratio, by 1.12–1.42 %. Through evaluating the compressive strength, it was found that the compressive strength of porous concrete with cementless binder decreased in comparison to the compressive strength of porous concrete with ordinary Portland cement (OPC), but the difference was insignificant, at 0.6–1.4 MPa. Through the freeze–thawing test to evaluate the durability, it was found that the relative dynamic elastic modulus of porous concrete with cementless binder decreased to 60 % or less at 80 cycles. The result of the chemical resistance test showed that the mass reduction rate was 12.3 % at 5 % HCl solution, and 12.7 % at 12.3 and 5 % H2SO4 solutions.

Permeability and Strength of Pervious Concrete According to Aggregate Size and Blocking Material

Abstract: The purpose of this study is to identify the differences in porosity and permeability coefficients when the mixing ratio of aggregates is different and to present the mixing ratio satisfying the strength requirement of compressive specified in a specification of Korea. Three mix ratios were suggested by considering various aggregate sizes and three cylinders were made for each ratio. The porosities of those cylinders were evaluated through the compression and water permeability test, measuring the weight of specimens in underwater and analysis of the pictured Computed Tomography (CT) image. Experiments have shown that it is best to mix 50% for 5–10 mm aggregates, 45% for 2–5 mm aggregates, and 5% for sand in terms of strength and permeability. In addition, as the proportion of fine aggregates increased, the porosity and permeability decreased. Moreover, the effectiveness of maintenance method was also examined in this study.