Experimental Study On Strength Curve Of High-strength Concrete By Ultrasonic Rebound Method In Handan Area

In today's society,concrete has become one of the indispensable materials in architecture.Among them,high-strength concrete has attracted more and more people's attention.High-strength concrete is used more and more in civil engineering.Therefore,the state has introduced relevant regulations.The standard gives the national unified strength curve of the ultrasonic rebound comprehensive method.In view of the fact that the national unified strength curve has a large difference with the actual strength of the concrete and the accuracy is not high enough in the application of high-strength concrete engineering in the Handan area,this paper combines the actual situation of the high-strength concrete engineering in the area of the Handan area to carry out the ultrasonic rebound comprehensive evaluation.Research on the strength of some high-strength concrete.The research content of this paper mainly includes:(1)Combined with the high-strength concrete in the concrete project in the concrete area,the actual materials used in the mix design,the representative raw materials in the region were used,and the strength grades were designed and produced as C50,C55,C60,C65,C70,C75.For the C80 high-strength concrete test block group,when the curing age is 7d,14 d,28d,60 d,90d,180 d and 365 d,the ultrasonic wave velocity detection is performed first for each test block,and then the rebound method is detected,and finally,Compressive strength test.(2)Selecting appropriate and representative mathematical models,respectively fitting the high-strength concrete ultrasonic rebound method strength curve corresponding to the ultrasonic instrument and two high-strength rebound hammers,and performing credibility analysis;The strength curve is compared and analyzed to obtain the ultrasonic rebound strength curve of high strength concrete which is more suitable for the area.(3)Based on the ultrasonic wave velocity,rebound value and compressive strength test results,a representative mathematical model of ultrasonic rebound comprehensive method was selected,and the ultrasonic rebound comprehensive method strength curve which is more suitable for high strength concrete in the area was established.(4)According to the research results of this paper,the ultrasonic rebound comprehensive strength measurement curve with high precision of high strength concrete in the sag area is given.