Porous concretes having suitable void ratios are produced with appropriate paste content and flow, and sufficient compaction. Cement paste with high viscosity and high flow suitable for making porous concrete is obtained with the use of low W/C of 0.20–0.25, an incorporation of 1% superplasticizer, and sufficient mixing. The results indicate that cement paste characteristics are dependent on the water to cement ratio (W/C), admixture and mixing time. From exfiltrate concentrations, nutrient retention was estimated to be 3.4 and 0.4 kg∕ha∕.read more read lessĪbstract: In this paper, cement paste characteristics and porous concrete properties are studied. However, no runoff was produced during this study from the Swansboro PICP site for rainfall events up to 88 mm. Runoff and exfiltrate samples were intended to be collected, in addition to runoff monitoring, from the Swansboro PICP site. Only the two permeable interlocking concrete pavement (PICP) sites were monitored for water quality. Measured runoff depths from rainfall events over 50 mm were used to determine permeable pavement equivalent curve numbers for the sites, which ranged from 45 to 85. One site of each pavement type was monitored for runoff reduction for periods ranging from 10 to 26 months. Sites were either constructed of permeable interlocking concrete pavers (2), porous concrete (1), or concrete grid pavers (1). This paper provides a basis for further study on the microscopic mechanism of porous concrete failure.read more read lessĪbstract: Four permeable pavement applications in North Carolina’s Coastal Plain were constructed and monitored to determine their effectiveness of reducing runoff quantity and improving water quality. During the failure process of porous concrete, cracks propagate into the pores until penetrating cracks occur. There are many connected or unconnected pores in porous concrete. The main failure mode of porous concrete under compression is the failure of the bonding layer between the aggregates, whereas the aggregate failure of conventional concrete rarely occurs. The mechanical properties and failure characteristics of porous concrete are different from those of conventional concrete. The results showed that the failure process of porous concrete could be divided into an initial stage, crack propagation stage and failure stage. In this research, the evolution of cracks and stress-strain curves of specimens under uniaxial compression were also analysed by the discrete element method (DEM). Based on acoustic emission (AE) technology, the changes in AE ringing counts and energy were recorded, and the b-value was analysed. To evaluate the damage and discuss the failure mechanism of porous concrete, a uniaxial compression test was carried out in this study. Beside that PCPB using CA 8 – 10 is able to remove surface runoff efficiently.Ībstract: Porous concrete is an environmentally friendly material. It was also shown that PCPB with CA 8 – 10 resulted in low strength, but high in porosity and permeability compared to the other blocks. It was found that the size of coarse aggregate affects the strength and porosity of the specimens. Furthermore, a series of test were conducted in this study such as compressive strength, porosity and permeability. Three different sizes of coarse aggregate were used passing 10 mm retained 5 mm (as Control), passing 8 mm retained 5 mm (CA 5 – 8) and passing 10 mm retained 8 mm (CA 8 – 10). The permeability and strength of PCPB with different sizes of coarse aggregate was presented in this study. TL DR: In this article, a series of test were conducted in this study such as compressive strength, porosity and permeability, and it was found that the size of coarse aggregate affects the strength and porosity of the specimens.Ībstract: Porous concrete paving block (PCPB) is a block with continuous voids which are intentionally incorporated into concrete.
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