高性能自密实透水混凝土的抗冻性研究

以高性能自密实混凝土为基体,通过钢筋预留直通孔制备可控孔隙率的自密实透水混凝土,研究不同混凝土孔隙率(0.636%、1.131%、1.508%、1.767%、2.011%、2.356%)和不同冻融介质(0和5%氯化钠溶液)与透水系数、抗压强度和抗冻性之间的关系。结果表明:高性能自密实透水混凝土的透水系数随孔隙率的增加而增大,且二者呈线性关系。养护28 d时,透水混凝土孔隙率从0.636%增大到2.356%,此时透水系数从5.192 mm/s增加到19.147 mm/s。预留直通孔混凝土可以实现低孔隙率下的高透水系数,不同冻融介质条件同样会对透水混凝土的抗压强度产生影响。以5%氯化钠溶液为冻融介质,冻融后的高性能透水混凝土在透水系数和抗压强度较0氯化钠溶液的介质下降的更为明显。

Study on frost resistance of high performance self-compacting pervious concrete

Based on high performance self-compacting concrete matrix,preparation of controllable porosity through reinforced the reserved through hole self-compacting pervious concrete and research on different concrete porosity(0.636%,1.131%,1.508%,1.767%,2.011%,2.356%)and different freezing and thawing media(0 and 5%sodium chloride solution)and permeable coefficient,the relationship between the compressive strength and frost resistance.The results show that the permeability coefficient of high performance self-compacting pervious concrete increases with the increase of porosity,and the relationship between them is linear.At 28 days of curing,the porosity of the pervious concrete increased from 0.636%to 2.356%,and the permeability coefficient increased from 5.192 mm/s to 19.147 mm/s.Retaining through-hole concrete allows for a high permeability coefficient at low porosity.Different freeze-thaw media conditions also have an effect on the compressive strength of the pervious concrete.With 5%NaCl solution as the freezing and thawing medium,the high-performance pervious concrete after freezing and thawing is more obvious in the permeability coefficient and the compressive strength lower than 0.