Research On Non-Destructive Testing Of Concrete

Concrete is one of the most important material of civil engineering.The quality of the structure concrete will affect the safety of structure directly.Traditional method of the structure concrete quality test base on the cube sample selected according to regulation.But for the production condition,maintain environment ,force bearing status etc of the sample are different with that of the structure concrete,Performance index of the test concrete sample is different with that of the actual structure concrete sometimes.So,locale testtechnology that test concrete quality in the structure directly has became an important method of concrete engineering quality management and is getting more and more recognition of every country in the word.To study the non-destructive test technique of concrete compressive strenth, 4 part investigation has been developed in this paper.1. Studying on the relationship between the rebound value, carbonation depth and concrete compressive strength, establishing curve for measuring strength to detect concrete compressive strength by rebound method for shandong province.2. Studying on the relationship between the rebound value,carbonation depth,sound speed and concrete compressive strength, establishing curve for measuring strength to detect concrete compressive strength with comprehensive method of ultrasonic and rebound for shangdong provence.3. Studying on the relationship between concrete pull-out resistance and concrete compressive strength, establishing curve for measuring strength to detect concrete compressive strength by pulling-out method for for shandong province.4. Studying on the 75mm diameter concrete core simples, compare the strength difference between 75mm and 100mm diameter cores, establishing the reliable conversion relationship between them.Correspond to the research, establishing formula of 4 measuring strength methods.1. The regression equation of rebound method for measuring strength to detect concrete compressive strength was f = 0 .03229N1. 934510(?0.0289d).2. The regression equation of comprehensive method of ultrasonic and rebound for measuring strength to detect concrete compressive strength was f = 0 .0072N1. 258V2.63210(?0.0154d).3. The regression equation of pulling-out method for measuring strength to detect concrete compressive strength was f = 2. 4607T0.8033.4. 75mm diameter and 1 height-diameters ratio concrete core simples can be used as the standard samples.On account of the concrete was composite material and low homogeneity, most of non-destructive test technique were indirect methods and have large quantity influence factors, so multiple technique for measuring concrete strength can be used to complement the insufficiency of testing methods.