A method for detecting the curing quality of early-age concrete based on time domain reflection

Abstract

The invention discloses a time domain reflection-based detection method for maintenance quality of early-stage concrete. The detection method comprises the following steps: preparing a concrete test piece at first and burying an exploration tube in the concrete test piece; in continuous maintenance date from pouring to hardening, measuring a plurality of groups of dielectric constants of the concrete test piece in each corresponding maintenance date by using a time domain reflectometer which is connected, through a cable, with a probe that is inserted into the exploration tube; calculating water content by using a drying method and a tool; calculating a coefficient in a function equation by using a least square method according to the function equation of the dielectric constants and the water content and determining a functional relationship between the dielectric constants of the concrete test piece and the water content; then determining a functional relationship between the strength of the concrete test piece and the water content; and in practical engineering, measuring the dielectric constant of newly-poured early-stage concrete by using the time domain reflectometer, calculating water content, and then according to target maintenance strength of the concrete, optimizing and adjusting maintenance conditions in real time and monitoring maintenance quality in real time. The detection method provided by the invention has the advantages of simple, convenient and rapid measurement, high precision and good stability.

Description

technical field [0001] The invention relates to a method for detecting the curing quality of early-age concrete, in particular to a method for detecting the curing quality of early-aged concrete based on time domain reflection, and belongs to the field of detecting concrete in the curing period. Background technique [0002] Concrete strength grade is an important indicator for evaluating concrete. The compressive strength of concrete is obtained through tests. The latest standard in my country with a strength below C60 uses a cube specimen with a side length of 100mm as the standard size specimen for concrete compressive strength. . According to GB / T50081-2002 "Standards for Test Methods of Mechanical Properties of Ordinary Concrete", a cube with a side length of 150 mm is made and maintained under standard curing conditions (temperature 20 ± 2°C, relative humidity above 95%) until the age of 28 days. The ultimate compressive strength measured by the standard test method is...

AI Technical Summary

Problems solved by technology

In the high-frequency electric field, the dielectric has relaxation loss, and the moisture in the concrete becomes an important part of the dielectric constant in the concrete, so the change of the humidity of the concrete can obviously change the dielectric properties of the concrete; by measuring the power attenuation, phase change The moisture content of concrete can be measured by using physical quantities related to dielectric constants such as resonance frequency and resonance frequency, but its disadvantage is that the research on the relationship between microwaves and water content is not deep enough to accurately obtain accurate moisture content.

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