CN105445318A - Temperature expansion testing method of semi-rigid base material of inorganic binding material - Google Patents

Abstract

The invention discloses a temperature expansion testing method of a semi-rigid base material of an inorganic binding material. According to the temperature expansion testing method, the transformation expansion amount of the length of a test piece of the semi-rigid base material at a high-temperature condition is determined through a high-low-temperature testing box. A testing device needed by the testing method comprises the high-low-temperature testing box and a dial indicator. By gradually raising a testing temperature, a semi-rigid base beam type test piece has high-temperature expansion and the change amount of the length of the test piece is recorded through the dial indicator, so that the high-temperature expansion property of the test piece in a process of gradually raising the temperature is evaluated, and an anti-cracking performance of the semi-rigid base material of the inorganic binding material is evaluated.

Description

A temperature expansion test method for inorganic binder semi-rigid base material

technical field

The invention belongs to the field of performance testing of inorganic binder semi-rigid base material.

Background technique

Relevant surveys and studies have shown that under high temperature conditions, the inorganic binder semi-rigid base material will expand due to the increase in temperature, and the stress generated by the expansion will cause the base to crack, bulge, and cause damage to the pavement . However, low-temperature shrinkage and drying shrinkage are used as indicators in evaluating the crack resistance of inorganic binder semi-rigid base materials, and high-temperature expansion is not considered. Therefore, it is of great significance to propose a test method for the temperature expansion of inorganic binder semi-rigid base materials to evaluate the crack resistance of semi-rigid base materials.

Contents of the invention

In the present invention, the initial temperature is 30°C, the test time is 16 hours, the test box is raised by 10°C every 4 hours, and the final temperature is 60°C; the semi-rigid base material specimen is expanded at high temperature, and each test piece is recorded by a dial gauge. The amount of change in length of the temperature phase. The total expansion is calculated from the change in each temperature stage. The high temperature expansion resistance performance was evaluated by the total expansion.

A temperature expansion test method for an inorganic binder semi-rigid base material, comprising the following steps;

(1) Make a semi-rigid base material beam-type test piece, make a standard test piece of 100mm×100mm×400mm according to the specification requirements, and keep the test piece in a standard environment for 7 days.

(2) In the last 1 day of health preservation, saturate the specimen with water for 24 hours and put it into an oven at 105°C to dry the specimen to constant weight.

(3) Cool the dried test piece to room temperature, paste glass sheets at both ends and put it into a high and low temperature test chamber with an initial temperature of 30°C, and measure its initial length L with a vernier caliper. After the test piece is kept warm for 4 hours, set up the dial gauge and reset the dial gauge.

(4) Increase the temperature of the test chamber by 10°C, adjust it to 40°C, and read the change of the dial gauges at both ends after holding the heat for 4 hours. The sum of the elongation of the two dial gauges is the total elongation of the test piece during the heating process. length. Denote the data as L1. Continue to clear the dial gauge after recording the data.

(5) Repeat step (4) until the temperature rises to 60°C, and record the obtained data as L2, L3...Li.

(6) The total expansion of the specimen is L1+L2...+Li.

(7) The thermal expansion performance of the specimen is evaluated by the total expansion. The greater the total expansion of the specimen, the worse the high temperature expansion resistance.

Thermal expansion and strain: ε _i = (L _i -L _i+1 )/L;

Coefficient of thermal expansion: δ _i =ε _i /(T _i -T _i+1 )

In the formula: L _i - the average value of the dial gauge readings in the i-th temperature interval;

T _i - the i-th temperature interval set by the temperature control program;

L - the initial length of the specimen;

ε _i - the average shrinkage strain at the i-th temperature (%);

_δi - coefficient of thermal expansion.

The present invention proposes for the first time a test method for evaluating the anti-crack performance of inorganic binder semi-rigid base material under the condition of elevated temperature. The larger the coefficient of expansion, the worse the crack resistance. This test is of great significance for evaluating the crack resistance of semi-rigid base materials.

Description of drawings

Fig. 1 is an assembly diagram of a temperature expansion test of an inorganic binder semi-rigid base material.

Claims (4)

1. an inorganic binder semi-rigid sub-base material temperature expansion test method, it is characterized in that the rising gradually of first passage temperature, cause test specimen generation high-temperature expansion, by its length expansion amount of clock gauge record, calculate warm swollen strain and its high temperature stability performance of the swollen factor evaluation of temperature.

2. a kind of inorganic binder semi-rigid sub-base material temperature expansion test method according to claim 1, it is characterized in that: test specimen is test specimen health 7d under Standard Curing condition of 100mm × 100mm × 400mm, health to be satisfied after water 24h and dry test specimen to constant weight, for test after cool to room temperature last day.

3. a kind of inorganic binder semi-rigid sub-base material temperature expansion test method according to claim 1, it is characterized in that the temperature of high-low temperature chamber from 30 DEG C to 60 DEG C every 10 DEG C of insulation 4h, each thermograde is by its length variations amount of clock gauge record.

4. a kind of inorganic binder semi-rigid sub-base material temperature expansion test method according to claim 1, after being recorded the high temperature variable quantity of test specimen, evaluates semi-rigid type base cracking resistance by clock gauge.