Correlation between Permeability and Porosity for Pervious Concrete (PC)

Abstract

The aim of this study was to propose a correlation for the hydraulic parameters of pervious concrete (PC). Thus, three aggregates from civil construction waste and one basalt aggregate (reference) were used to produce PC. The ratio c/a (cement: aggregate) 1:3.26 and a w/c ratio of 0.34 were used in all mixtures. Compressive and flexure tensile strength tests were performed to mechanically characterize the mixtures produced, whereas porosity and constant head permeability tests were also carried out to assess the material hydraulic properties.Firstly, the experimental results were compared with the requirements established in international guidelines (ACI 522R-10, NBR 16416(2015) and VTT-R-080225-13). The results complied with the guidelines indicating it is feasible to produce pervious concretes with the sustainable aggregates used in the study in low structural applications such as walkways. On the other hand, a correlation between permeability and porosity was proposed based on Darcy’s and Bernoulli’s laws. The proposed equation, obtained by means of a non-linear regression, is an exponential equation that characterizes the hydraulic efficiency of the internal channels of the material considering the pores interconnection. The correlation between porosity and permeability was finally validated using results from the literature showing the same trend found in laboratory, and therefore it was demonstrated that the proposed correlation in an efficient tool to predict the hydraulic efficiency of pervious concrete.

Influence of compaction energy on pervious concrete properties and vertical porosity distribution

“…Figure 14 shows that for a certain mixture, the porosity can also be estimated by the compaction energy (Equation 1). Porosity, in turn, is the parameter that most affects the pervious concrete hydraulic conductivity [65]. Although Equation 4 may be used to describe the material hydraulic behavior, the relation between porosity and hydraulic conductivity may be represented by a simpler regression model, based on the Kozeny-Carman equation [34], [66], presented in Equation 5.…”

Hydraulic Performance of Pervious Concrete Based on Small Size Aggregates

“…e above results are on par with Fu et al [45], where porosity increases with aggregate size. Ibrahim et al [46] calculated the density for aggregate-cement ratio of 8, water-cement ratio of 0.35 Sandoval et al [11] Cai et al [42] Azad et al [13] Zhu et al [43] Lori et al [14] e current paper 4. e concrete mix has porosity values in tandem with the literature as shown in Figure 6.…”

“…e governing equations and their R 2 values are tabulated in Table 7. e x values are the 0 Mohammed et al [44] Sandoval et al [11] Cai et al [42] Azad et al [13] Zhu et al [43] Lori et al [14] e current paper Sandoval et al [11] Cai et al [42] Azad et al [13] Zhu et al [43] Lori et al [14] e current paper Comparing the permeability due to clogging with the standards tabulated in Table 4, the clogging of clay and sand on the pervious concrete with the narrow gradation of 2.36-4.75 mm causes the permeability value to go below the minimum value of 1 mm/s as per the American guidelines ACI 522R-10 and the Brazilian standards NBR 16416 : 2015. Also, after the first clogging cycle on the above mix, the value is below the minimum of 1.5 m/s as per the guidelines by Finland Technical Research Center VTT-R-080225-13.…”

Stormwater Runoff Treatment Using Pervious Concrete Modified with Various Nanomaterials: A Comprehensive Review

“…In another study, PC specimens were produced using basalt aggregates with a specific size of 4.75-9.5 mm, and #42.5 Portland cement [11]. Basalt aggregates had a larger fine grain content than the other types, reducing the ultimate porosity [139]. Accord-ing to Table 1, the dry density, saturated density, bulk density and water absorption of basalt aggregates were 2230 kg/m 3 , 2670 kg/m 3 , 1500 kg/m 3 and 1.20%, respectively.…”