Showing papers on "Pervious concrete published in 1989"

The Effect of Curing on the Strength and Permeability of PFA Concrete

Abstract: This paper describes how tests were carried out on a series of concrete mixes that were designed to equal workability and compressive strength with a range of pulverized fuel ash (PFA) levels in order to study the effect of curing on the strength and permeability of PFA concrete. Concrete specimens were subjected to a range of moist-curing periods prior to air storage. Compressive strength was determined at various ages and permeability to oxygen and water was determined at 28 days. Results confirm the importance of curing, with reductions in the curing period resulting in lower strength, more permeable concrete. The strength of the PFA concretes appears to be more sensitive to poor curing than ordinary portland cement (OPC) concrete, the sensitivity increasing with increasing PFA content. However, despite exhibiting lower strengths, PFA concretes moist-cured for only one day were, generally, no more permeable to water and substantially less permeable to oxygen than similarly cured OPC concretes. As the period of curing increased, the PFA concretes became considerably more impermeable to water and oxygen than the OPC concretes. These results are discussed in the context of the minimum periods of curing and protection recommended in BS 8110. It is argued that although the increased curing periods suggested for PFA concrete are justified on the basis of concrete strength, PFA concrete may require no more curing than OPC concrete to achieve equal durability, as measured by oxygen and water permeability.

Block for constructing elastic floor paved road surface and manufacture thereof

Abstract: PURPOSE: To reduce cost by constituting a polyurethane resin layer and a primer layer and a block layer selected from concrete, mortar, permeable concrete or resin concrete by structure in the order. CONSTITUTION: Crushed stones are laid and a foundation subgrade layer 1 is formed by the rolling of a roller or the like, and the uneven adjustment and cushioning material layer 2 of a foundation subgrade is laid on the layer 1. A block layer 3 selected from a concrete block, a mortar block, a permeable concrete block or a resin concrete block is formed in a preformed or amorphous solid design form such as a triangle pole-an octagonal pole or a column or the like, and irregularities are formed to side faces for joining with adjacent blocks. One pack type moisture cured polyurethane resin is used as a primer layer 4, and a polyurethane resin layer 5 having a pattern is built on the layer 4. Accordingly, follow-up properties can be improved to the deformation of the subgrade.

Water pervious concrete structure

Abstract: PURPOSE: To increase strength regardless of the shape of a concrete structure while improving corrosion resistance by arranging nonmetal and rustproof high-performance continuous fibers into a structure body as a reinforcing material. CONSTITUTION: A reinforcing material 3 comprising nonmetal and rustproof high-performance continuous fibers such as aramid fibers, carbon fibers, glass fibers or the like into a structure body 2 composed of permeable concrete.

Sound-insulating and sound-reducing drains element open porous concrete construction. (Machine-translation by Google Translate, not legally binding)

Abstract: Construction element sound & sound-reducing drains concrete porous open, wherein the component slabstock presents at least one side layer of concrete pores filled normal, whose grain size is less than 4 mm, and other normal concrete layer and the two layers are connected together monolithically. (Machine-translation by Google Translate, not legally binding)

Evaluation of absorptive sound barrier samples in freeze/thaw environments

Abstract: An experiment was conducted to determine the resistance of absorptive sound barriers to repeated cycles of freezing and thawing. Testing was performed on two absorptive sound barrier samples of porous concrete on one side of the panel and normal concrete on the other. Embedded only in the surface of the porous concrete were 1-in smooth aggregate pieces. The two concretes differed in such properties as strength, mix proportions, and density. The details of the tests and results are presented. It was found that the resistance of the porous concrete specimens to freeze/thaw conditions was poor and resulted in considerable loss of section. Such porous concrete samples were determined to be unsuitable as absorptive sound barriers in situations where they will be subjected to repeated freeze/thaw cycles.