超声回弹综合法检测橡胶混凝土的测强曲线

分别以C10、C20、C30、C40和C50强度等级的普通混凝土为基准,选取3 mm~6 mm、1 mm~3mm和60目三种粒径橡胶颗粒,分别以砂体积的5%、10%、15%和20%等体积取代部分砂配制橡胶混凝土,采用超声回弹综合法对各类混凝土进行测强试验,其中回弹仪采用中型回弹仪和轻型回弹仪两种,得到两种测强曲线,比较得出橡胶混凝土适用的回弹仪类型和超声回弹综合检测方法。试验结果显示:超声回弹综合法检测基准混凝土和橡胶混凝土的测强曲线的平均相对误差均满足《规程》要求,但掺加3 mm~6 mm和1 mm~3 mm橡胶颗粒的混凝土的测强曲线精度较基准混凝土低,而掺加60目橡胶颗粒的混凝土的测强曲线精度较基准混凝土高;对基准混凝土和掺加3 mm~6 mm橡胶颗粒的混凝土,采用中型回弹仪比轻型回弹仪能够得到较高精度的测强曲线,对掺加1 mm~3 mm和60目橡胶颗粒的混凝土,采用轻型回弹仪比中型回弹仪能够得到较高精度的测强曲线。

Detection of Rubber Concrete Strength by Ultrasonic Method

With C10 ,C20 and C30 ,C40 and C50 strength grade of ordinary concrete as the benchmark ,choose 3 mm ~6 mm ,1 mm ~ 3 mm and 60 mesh three kinds of particle size of rubber particles ,sand respectively by 5% ,10% ,15%and 20% of the volume to partly replace sand mixing rubber concrete ,such as volume of the various kinds of concrete by ultrasonic rebound synthesis strength test .In the test ,the rebounder is used in two kinds of high-medium-and light-re-bounder ,and two kinds of strong curves are obtained ,which can be used to compare the type of elastic and ultrasonic re -bound method .Test results showed that ultrasonic rebound synthetic method to detect the benchmark concrete and rubber concrete strength curve of the average relative error can satisfy the requirements of the regulation ,but adding 3 mm ~ 6 mm and 1 mm ~ 3 mm rubber particles of concrete strength curve precision was lower than those of benchmark concrete , and adding 60 mesh precision of concrete strength curve of rubber particles is high benchmark concrete ;Benchmark for concrete and concrete mixed with 3 mm ~ 6 mm rubber particles ,using medium hammer than light hammer can get higher accuracy measurement curves ,the mixed with 1 mm ~ 3 mm and 60 mesh rubber particles of concrete ,adopting light hammer than medium elasticity tester can get higher accuracy of measuring curves .