混凝土裂缝快速修补胶浆的制备及性能研究

Study on Preparation and Properties of Quick Repair Mortar for Concrete Crack

以超细硅酸盐水泥和超细硫铝酸盐水泥为基准材料,以苯丙乳液和纳米SiO_(2)为改性剂制备了一种混凝土桥梁底板裂缝快速修补胶浆,通过研究改性剂掺量对修补胶浆流动度和凝结时间的影响,确定了其最佳配合比,研究了苯丙乳液掺量对修补胶浆拉伸性能和强度的影响。结果表明:修补胶浆的最佳配合比为:m(超细水泥)∶m(水)∶m(纳米SiO_(2))∶m(苯丙乳液)=100∶60∶2∶9;在此配合比下,该修补胶浆的初凝时间为56 min,终凝时间为64 min,初始流动度和30 min流动度分别为250 mm和65 mm,28 d抗压强度和抗折强度分别为19.4 MPa和6.1 MPa,折压比为31.4%,与裂缝壁的黏结强度为2.57 MPa;该修补胶浆施工性能、强度和韧性优良,与裂缝壁黏结性能良好,可确保裂缝修补后的使用耐久性。

With ultrafine portland cement and ultrafine sulphoaluminate cement as the base materials,with styrene-acrylic emulsion and nano-SiO_(2) as modifiers,a kind of quick repair mortar for concrete bridge base crack was prepared.The optimal mix property of modifier was determined by studying the influence of modifier content on the fluidity and setting time of repair mortar.The effect of the content of styrene-acrylic emulsion on the tensile properties and strength of the repair mortar was systematically studied.The results show that the optimal mix proportion of repair mortar is:m(ultra-fine cement)∶m(water)∶m(nano-SiO_(2))∶m(styrene-acrylic emulsion)=100∶60∶2∶9.Under the optimal mix proportion,the initial setting time of the repair mortar is about 56 min,and the final setting time is 64 min,the initial fluidity and the fluidity after 30 minutes are 250 mm and 65 mm.The 28 d compressive strength and flexural strength are 19.4 MPa and 6.1 MPa respectively,and the flexural ratio is 31.4%,and the bond strength to the crack wall is 2.57 MPa.The repair mortar has excellent construction performance,strength and toughness,and has good bonding performance with the crack wall,which can ensure the durability after the crack is repaired.