钢筋连接用套筒灌浆料组成因素对其性能影响的研究

Study on the influence of composition factors of cementitious grout for sleeve of rebar splicing on its performance

通过测试钢筋连接用套筒灌浆料的流动度、抗压强度及竖向膨胀率,研究了骨料级配、水胶比、胶砂比、矿物掺合料及膨胀剂5种组成因素对套筒灌浆料性能影响的规律,并采用扫描电子显微镜对灌浆料硬化浆体进行微观形貌分析。试验结果表明:粗颗粒骨料比例的增大可以提高套筒灌浆料流动度且有利于后期抗压强度的发展;水胶比为0.25时套筒灌浆料性能最优,初始流动度为360、30 min流动度保留值为335 mm,1、3、28 d抗压强度分别为56.4、78.4、97.1 MPa;胶砂比在1-1.1∶1时,套筒灌浆料流动度和抗压强度较为理想;与粉煤灰和磷渣粉相比,矿渣粉更适合作为活性掺合料,其合理掺量为9%,轻质碳酸钙作为填料可以提高套筒灌浆料的抗压强度,但也降低了流动度。采用普通硅酸盐水泥作为基质胶凝材料时,SCA膨胀剂对套筒灌浆料体积稳定性的贡献要优于MEA膨胀剂。

By testing the fluidity,compressive strength and vertical expansion rate of cementitious grout for sleeve of rebar splicing,the influence of aggregate gradation,water binder ratio,cement sand ratio,mineral admixture and expansion agent on the performance of cementitious grout for sleeve were studied.Then the micro-morphology was analyzed by the scanning electron microscope(SEM).The test results show that the increase of coarse aggregate proportion can improve the fluidity of cementitious grout for sleeve and is conducive to the development of later compressive strength.When the water binder ratio is 0.25,the performance of cementitious grout for sleeve is the best,the initial fluidity is 360 mm,the 30 min retention value of fluidity is 335 mm,and the compressive strength of 1,3 and 28 d are 56.4,78.4 and 97.1 MPa respectively.When the ratio of rubber to sand is 1-1.1∶1,the fluidity and compressive strength of the cementitious grout for sleeve are relatively ideal.Compared with fly ash and phosphorus slag powder,the slag powder is more suitable as active admixture,and its reasonable content is 9%.As filler,the light calcium carbonate can improve the compressive strength of cementitious grout for sleeve,but also reduce the fluidity.When the ordinary portland cement is used as matrix cementitious material,the contribution of SCA expansion agent to volume stability of cementitious grout for sleeve is better than that of MEA expansion agent.