ASTM C597-16
混凝土脉冲速度的标准试验方法

Standard Test Method for Pulse Velocity Through Concrete

被代替

标准号

ASTM C597-16

发布

2016年

发布单位

美国材料与试验协会

替代标准

ASTM C597-22

当前最新

ASTM C597-22

 

 

引用标准

ASTM C125 ASTM C215 ASTM C823 ASTM E1316

适用范围

5.1 The pulse velocity, V, of longitudinal stress waves in a concrete mass is related to its elastic properties and density according to the following relationship:

where:
E	=	dynamic modulus of elasticity,
μ	=	dynamic Poisson's ratio, and
ρ	=	density.

5.2 This test method is applicable to assess the uniformity and relative quality of concrete, to indicate the presence of voids and cracks, and to evaluate the effectiveness of crack repairs. It is also applicable to indicate changes in the properties of concrete, and in the survey of structures, to estimate the severity of deterioration or cracking. If used to monitor changes in condition over time, test locations are to be marked on the structure to ensure that tests are repeated at the same positions.

5.3 The degree of saturation of the concrete affects the pulse velocity, and this factor must be considered when evaluating test results (Note 1). In addition, the pulse velocity in saturated concrete is less sensitive to changes in its relative quality.

Note 1: The pulse velocity in saturated concrete may be up to 58201;% higher than in dry concrete.3

5.4 The pulse velocity is independent of the dimensions of the test object provided reflected waves from boundaries do not complicate the determination of the arrival time of the directly transmitted pulse. The least dimension of the test object must exceed the wavelength of the ultrasonic vibrations (Note 2).

Note 2: The wavelength of the vibrations equals the pulse velocity divided by the frequency of vibrations. For example, for a frequency of 548201;kHz and a pulse velocity of 3500 m/s, the wavelength is 3500/54000 = 0.065 m.

5.5 The accuracy of the measurement depends upon the ability of the operator to determine precisely the distance between the transducers and of the equipment to measure precisely the pulse transit time. The received signal strength and measured transit time are affected by the coupling of the transducers to the concrete surfaces. Sufficient coupling agent and pressur......

混凝土压力试验机检验方法

混凝土压力试验机耐运输颠簸性能的检验:      试验机的耐运输点破性能可使用下述两种方法之一进行检验：     a） 将试验机的包装件按正常的运输状态紧固安装在碰撞台的台面上，以近似半正弦波的脉冲波形进行碰撞试验，实验时选用的严酷等级如下：峰值加速度100m/s2±10m/s2,脉冲持续时间11ms±2ms，脉冲重复频率60次/min~100次/min，碰撞次数1000次±10次。   ...