卵石混凝土长期弹性模量无损测试试验研究

Experimental Research on the Long-term Elastic Modulus of Pebble Concrete by Nondestructive Detection

为克服混凝土弹性模量传统测试方法的不足,采用超声波平测法,开展了卵石混凝土长期弹性模量无损测试试验研究。通过超声波无损测试,获取声波在卵石混凝土传播中的纵波与表面波的波速,可计算出它的长期动弹性模量。对一批不同强度等级的卵石混凝土试件进行了长期静、动弹性模量试验,采用数值拟合的方法,将试验结果进行线性回归,构建了5~20 mm和5~30 mm两种粒径的卵石混凝土静、动弹性模量的转换公式,并将研究成果应用于一座预应力混凝土桥梁的长期弹性模量无损测试中,它为卵石混凝土的长期弹性模量无损测试奠定了基础。

In order to overcome the deficiencies of the traditional detection methods of elastic modulus of concrete,the experimental research on the long-term elastic modulus of pebble concrete by nondestructive detection was carried out by using of ultrasonic single side method. The longitudinal wave velocity and surface wave velocity of sound wave propagation in pebble concrete can be obtained by ultrasonic nondestructive detection,and then the long-term dynamic elastic modulus of pebble concrete can be calculated. Experiment on the long-term static and dynamic elastic modulus of a group of pebble concrete specimens with different strength grades was carried out. Linear regression was carried out with the experimental results by the method of numerical fitting,and then the conversion formula between static elastic modulus and dynamic elastic modulus of pebble concrete with particle sizes of 5 ～ 20 mm and 5 ～ 30 mm was set up. The research results were applied to the nondestructive detection of the long term elastic modulus of a prestressed concrete bridge. It can lay the foundations of nondestructive detection of the longterm elastic modulus of pebble concrete.