Issue 46

Y. Yanya, Frattura ed Integrità Strutturale, 46 (2018) 343-351; DOI: 10.3221/IGF-ESIS.46.31 348 strength of RC100D was about 35.4% higher than that of RC100, indicating that grading adjustment could optimize the strength of pervious concrete. Grading adjustment could improve the stacking density and decrease the crushing value, which could improve the compressive strength and reduce dispersion. Compressive strength / MPa Figure 3 : Compressive strength of the recycled pervious concrete. 0 20 40 60 80 100 0 2 4 6 8 10 Replacement rate/% RC0 RC30 RC50 RC100D RC100 Figure 4 : The diagram of the relationship between different replacement rate and compressive strength. The compressive strength was considered in an exponential relationship with the porosity, and the compressive strength decreased with the increase of the porosity [17]. The relationship between the porosity and compressive strength found in this study was basically consistent with previous studies (Fig. 5 and 6). But RPC100 with the largest porosity, surprisingly, had the highest compressive strength. The compressive strength of porous pervious concrete is usually determined by the occlusion friction of coarse aggregate and the bounding strength between aggregate and cement mortar. The rough surface of RPC100 increased the occlusion friction between aggregate, and moreover the thickness of cement mortar between aggregate increased. Compressive strength / MPa Figure 5 : Porosity and compressive strength.