Establishment And Application Of High Strength Concrete Rebound And Ultrasonic Rebound Strength Curve In Hefei Area

The use of rebound method and ultrasonic rebound method to detect concrete strength has a very wide application background in construction engineering.To this end,the state has established the rebound method and the ultrasonic rebound method strength curve,but this is established for the whole country.Whether it is applicable to the Hefei area needs to be verified.If the accuracy cannot be met by the experiment,it is necessary to set up another regional strength.curve.This project produces C40-C60 high-strength concrete test blocks of different strength grades in the laboratory.The four basic parameters of concrete are measured,mainly the rebound value,wave velocity value,carbonization depth and concrete compressive strength.To verify whether the national rebound strength and ultrasonic rebound strength curve can be used in Hefei area,based on this research,establish a curve of high-strength concrete rebound and ultrasonic rebound strength applicable to Hefei this area.Study early prediction methods for high-strength concrete strength.The final results of the study indicate that the national ultrasonic rebound strength curve is not suitable for use in Hefei.The relative standard deviation and relative error of the two are 24.1% and 19.7%,respectively,which do not meet the relevant requirements of the current regulations and need to be re-established.It belongs to the local intensity curve of Hefei.The newly established rebound strength curve equations are: and,the relative error and relative standard deviation of the high-strength concrete ultrasonic rebound strength curve are 9.7%and 12.5%,respectively.The relative error and relative standard deviation of the high-strength concrete rebound strength curve are respectively At 8.8% and 11.2%,it is able to meet the requirements.It also shows that the strength curve of Hefei can be used to predict the strength of high-strength concrete.Using the newly established strength curve to predict the early strength of concrete,and to study the relationship between the strength of concrete at late age and the strength of early age concrete,and obtain a general method for estimating the strength of late age by early age strength.Therefore,the strength of high-strength concrete is predicted in advance,so as to find problems in the project as early as possible,which has a strong practical significance for construction.