基于振动搅拌的混凝土性能试验研究

Experimental Study on Concrete Performance Based on Vibration Mixing

以河南省栾川至卢氏高速公路为工程依托,采用工地实验室试验机与拌合站工业机相结合的方式,对混凝土在振动搅拌和普通搅拌2种拌和方式下的工作性能进行对比试验研究。结果表明:1)振动搅拌C30混凝土3 d、7d、28 d龄期抗压强度分别达到90 d龄期抗压强度的45. 4%、69. 6%、93. 1%,混凝土抗压强度在早期提升较快,后期放缓;2)振动搅拌C30、C40、C50混凝土28 d龄期抗压强度比普通搅拌分别高出19. 0%、8. 1%、6. 2%,当混凝土设计强度等级提高时,振动搅拌对混凝土强度形成的影响逐渐减弱;3)当水泥用量减少8%时,振动搅拌混凝土抗压强度降低了7. 8 MPa,而普通搅拌则降低了10. 6 MPa,水泥含量降低时,振动搅拌方式对混凝土的抗压强度具有补偿作用,利于节约水泥;4)与普通搅拌方式相比,振动搅拌方式下C30混凝土含气量可提高0. 1%~0. 7%,坍落度可增加10 mm~15 mm。

Based on the Luanchuan-Lushi Expressway in Henan Province,a comparative study on the working performances of concrete mixed by the vibratory and conventional methods has been conducted by combining the testing machine in the site lab and the industrial machine of the mixing station.The results show that the compressive strength of C30 concrete mixed by vibration at 3 d,7 d and 28 d age is 45.4%,69.6% and 93.1% of that at 90 d age respectively.Concrete mixed by the vibratory method increases faster in the early stage and then gradually slows down.The 28d compressive strength of C30,C40 and C50 concrete mixed with vibration is 19.0%,8.1%and 6.2% higher than that of ordinary mixing respectively.As the design strength of the concrete increases,the positive influence of the vibratory mixing method on the concrete strength formation decreases.When the cement content is reduced by 8%,the compressive strength of vibration mixing concrete is reduced by 7.8 MPa,while that of ordinary mixing concrete is reduced by 10.6 MPa.The vibratory mixing method has a compensating effect on the compressive strength of concrete with a lower content of cement,which is beneficial to save cement consumption.Compared with ordinary mixing method,the air content of C30 concrete under vibration mixing method can be increased by 0.1%~0.7%,and the slump can be increased by 10 mm~15 mm.