孔径对新型透水混凝土耐磨性的影响研究

Study on the influence of pore size on the abrasion resistance of new permeable concrete

采用预置钢筋以形成上下直通孔的新型自密实透水混凝土,具有强度高、透水性好且不易堵塞的优点。然而,孔径尺寸及排布方式对新型透水混凝土耐磨性能影响及规律还未得知,为此,基于花轮片法表面磨损试验,探讨不同孔径下新型透水混凝土的耐磨性演化规律。结果表明:与传统透水混凝土相比,新型透水混凝土的透水性能及抗压强度具有显著优势的同时,其耐磨性也满足公路水泥混凝土路面规范中的要求。单位面积磨损量和磨损深度均表明新型透水混凝土的表面耐磨性与预留孔的孔径呈负相关,但孔径对试件耐磨性的削弱不大,5 mm试件的磨损量仅比1 mm试件多14%。考虑新型透水混凝土的特殊构造,磨损深度更适合表征其耐磨性。对耐磨机磨损圈数与试件磨损深度进行曲线拟合,各孔径试件均表现出类似的变化规律,即随着耐磨机磨损圈数的增大总体呈增加趋势,但由于混凝土表层与内部存在耐磨性差异,磨损深度增速随之不同,磨损深度先缓慢增加,后快速增加,最后趋于稳定,且随着孔径增大试件磨损深度增速加快。综合考虑堵塞情况、耐磨性及透水性,推荐孔径为2~3 mm。

A new type of self-compacting permeable concrete that uses preset steel bars to form through holes has the advantages of high strength,water permeability and not easy to block.However,the influence of pore size and arrangement on the wear resistance of new permeable concrete has not been known.Therefore,it discusses the evolution of the abrasion resistance of the new permeable concrete with different pore diameters based on the surface wear test of the flower disc method.The results show that,compared with traditional permeable concrete,the new permeable concrete has significant advantages in water permeability and compressive strength,and its wear resistance also meets the requirements of highway cement concrete pavement specifications.The amount of wear per unit area and the depth of wear indicate that the surface wear resistance of the new permeable concrete is inversely related to the pore size of the reserved hole,but the pore size has little effect on the wear resistance of the test piece.The wear of the 5 mm specimen is only 14%more than the 1 mm specimen.Considering the special structure of the new permeable concrete,the wear depth is more suitable for characterizing its wear resistance.Curve fitting of the number of wear rings of the wear-resistant machine and the depth of wear of the test piece,the test specimens of each aperture show similar changes,that is,the wear depth increases with the increase of the number of wear rings of test machine,but due to the surface layer of the concrete.There is a difference in wear resistance from the inside,and the growth rate of the wear depth is different.The wear depth slowly increases first,then increases rapidly,and finally tends to be stable.As the pore size increases,the increase in the depth of wear of the test piece accelerates.Considering the blockage,abrasion resistance and water permeability,the recommended pore size is 2~3 mm.