CN204514837U

CN204514837U - For the portable test unit of thermal expansion coefficient of concrete test

Info

Publication number: CN204514837U
Application number: CN201520192403.0U
Authority: CN
Inventors: 曾飞; 陈英豪; 孙斌; 彭双阳
Original assignee: Gezhouba Group Cement Co Ltd
Current assignee: Gezhouba Group Cement Co Ltd
Priority date: 2015-04-01
Filing date: 2015-04-01
Publication date: 2015-07-29
Anticipated expiration: 2025-04-01

Abstract

For the portable test unit of thermal expansion coefficient of concrete test, relate to cement experiment apparatus field, it comprises heating rod (1), metallic bellows (2), temperature controller (3), die trial (4), contactless deformation tester (5), insulation can (6) and temperature sensor (7), metallic bellows (2) is enclosed within heating rod (1), temperature controller (3) controls the heating-up temperature of heating rod (1), die trial (4) is respectively equipped with and builds mouth, a pair deformation test instrument probe mounting interface and metallic bellows passing hole, metallic bellows (2) is positioned at the metallic bellows passing hole of die trial (4), this device build the scale of construction little, save physical material resources, testing efficiency is high, obey principle that concrete progressively heats from inside to outside, measuring accuracy is high.

Description

For the portable test unit of thermal expansion coefficient of concrete test

Technical field

The utility model relates to cement experiment apparatus field, is specifically related to the portable test unit for thermal expansion coefficient of concrete test.

Background technology

Along with development that is economic and science and technology, mass concrete not only generally uses in hydro-structure, also large volume concrete structural is belonged at the base plate in civil construction field, and along with the rise of high-rise high-rise building, occur and the distinct high-strength large volume shear wall structure of building field and steel plate-concrete combined shear wall structure in the past, such massive structure is generally again main force structure or component, once there is cracking, the free area size of direct reduction structural elements, reduce bearing capacity, simultaneously, the appearance in crack can make air, hazardous medium in the environment such as water gos deep into concrete bodies inside by crack, seriously undermine the permanance of concrete structure member.

The principal element affecting mass concrete cracking is: 1, differential contraction stress, and xoncrete structure shrinks effect in-service all the time, when concrete contraction is subject to external constraint, produces differential contraction stress; 2, temperature stress, mass concrete, between Binder Materials hydration period, produces a large amount of hydration heat, and hydration heat is accumulated in xoncrete structure inside and not easily scatters and disappears, cause internal temperature high, and outside is by dispelling the heat with environmental exposure, cause external temperature low, thus, larger thermograde is formed inside and outside large volume concrete structural, make concrete self produce constraint stress, under outside effect of contraction, produce outside bound stress simultaneously; Therefore, when the differential contraction stress of mass concrete superposes with temperature stress and exceedes concrete tensile strength, mass concrete ftractures.

In two kinds of factors of mass concrete cracking, concrete contraction can test acquisition easily in laboratory, and concrete temperature deformation is difficult in laboratory obtain, usually by the concrete thermal expansivity accounting temperature distortion of test, therefore the test of thermal expansivity judges most important to the temperature deformation of mass concrete, temperature stress, splitting resistance.

At present, the method obtaining thermal expansion coefficient of concrete is generally:

1, while carrying out Adiabatic temperature rise of concrete test, concrete thermal expansivity is tested.

2, adopt baking oven, concrete sample is positioned in baking oven, by baking oven two side hole, carbon-point etc. is settled by concrete sample, and connects the instruments such as clock gauge, by baking oven set temperature, test concrete thermal expansivity.

But two kinds of proving installations all have deficiency: the first device concreting scale of construction is excessive, at substantial manpower and materials, and test efficiency is low, and measuring accuracy is not high; The second device implements the type of heating of ecto-entad to concrete sample by baking oven, run counter to the mechanism that concrete body hydration heat conducts heat from inside to outside, change the mechanism of inner hydration rate faster than outside, and be difficult to the heat conduction avoiding carbon-point, be installed on the larger test error that the outside clock gauge of baking oven and oven interior temperature difference cause.

Therefore, in order to test thermal expansion coefficient of concrete, be badly in need of invention one build the scale of construction little, save physical material resources, testing efficiency is high, obey the principle that concrete progressively heats from inside to outside, the portable test unit that measuring accuracy is high.

Utility model content

The purpose of this utility model is exactly to solve the problems of the technologies described above, and is provided for the portable test unit of thermal expansion coefficient of concrete test.

The utility model comprises heating rod, metallic bellows, temperature controller, die trial, contactless deformation tester, insulation can and temperature sensor, metallic bellows is enclosed within heating rod, temperature controller controls the heating-up temperature of heating rod, die trial is respectively equipped with and builds mouth, a pair deformation test instrument probe mounting interface and metallic bellows passing hole, metallic bellows is positioned at the metallic bellows passing hole of die trial, two inductive probes of contactless deformation tester are arranged in a pair deformation test instrument probe mounting interface of die trial respectively, temperature sensor detects the temperature of insulation can.

Die trial material is steel, and the shaping concrete sample of die trial is of a size of 100 × 100 × 515mm.

Temperature sensor is the temperature sensor with temperature indicator.

Heating rod is resistance-type heating rod.

The utility model advantage is: this device build the scale of construction little, save physical material resources, testing efficiency is high, obey principle that concrete progressively heats from inside to outside, measuring accuracy is high.

Accompanying drawing explanation

Fig. 1 is the utility model structural representation.

Embodiment

As shown in Figure 1, the utility model comprises heating rod 1, metallic bellows 2, temperature controller 3, die trial 4, contactless deformation tester 5, insulation can 6 and temperature sensor 7, metallic bellows 2 is enclosed within heating rod 1, temperature controller 3 controls the heating-up temperature of heating rod 1, die trial 4 is respectively equipped with and builds mouth, a pair deformation test instrument probe mounting interface and metallic bellows passing hole, metallic bellows 2 is positioned at the metallic bellows passing hole of die trial 4, two inductive probes of contactless deformation tester 5 are arranged in a pair deformation test instrument probe mounting interface of die trial 4 respectively, temperature sensor 7 detects the temperature of insulation can 6.

Die trial 4 material is steel, and the shaping concrete sample of die trial is of a size of 100 × 100 × 515mm.

Temperature sensor 7 is the temperature sensors with temperature indicator.

Heating rod 1 is resistance-type heating rod.

Working method and principle: during use, first start-up temperature controller 3, complete after temperature rise rate and target temperature arrange, start-up temperature sensor 7, after concrete sample final set, remove the side plate of die trial 4, start the initial length that contactless deformation tester 5 monitors the rear test specimen of side plate dismounting of die trial 4, after temperature controller 3 reaches target temperature, observe when the temperature of temperature sensor 7 is consistent with temperature controller 3 temperature time, record the data of contactless deformation tester 6, for test end of a period data, according to above test figure and concrete contraction test data, concrete thermal expansivity can be calculated.

The calculating of thermal expansion coefficient of concrete:

a=((L2-L1)/ L1)/(T2-T1)

In formula: a---thermal expansion coefficient of concrete (× 10-6/ DEG C);

T1---concrete sample enters the initial temperature (DEG C) of insulation can;

The design temperature (DEG C) of T2---concrete sample in insulation can;

The initial length of L1---concrete sample when temperature is T1 (mm);

The length (mm) of L2---concrete sample when design temperature T2.

Claims

1. for the portable test unit of thermal expansion coefficient of concrete test, it is characterized in that it comprises heating rod (1), metallic bellows (2), temperature controller (3), die trial (4), contactless deformation tester (5), insulation can (6) and temperature sensor (7), metallic bellows (2) is enclosed within heating rod (1), temperature controller (3) controls the heating-up temperature of heating rod (1), die trial (4) is respectively equipped with and builds mouth, a pair deformation test instrument probe mounting interface and metallic bellows passing hole, metallic bellows (2) is positioned at the metallic bellows passing hole of die trial (4), two inductive probes of contactless deformation tester (5) are arranged in a pair deformation test instrument probe mounting interface of die trial (4) respectively, temperature sensor (7) detects the temperature of insulation can (6).

2. the portable test unit for thermal expansion coefficient of concrete test according to claim 1, is characterized in that die trial (4) material is steel, and the shaping concrete sample of die trial is of a size of 100 × 100 × 515mm.

3. the portable test unit for thermal expansion coefficient of concrete test according to claim 1, is characterized in that temperature sensor (7) is the temperature sensor with temperature indicator.

4. the portable test unit for thermal expansion coefficient of concrete test according to claim 1, is characterized in that heating rod (1) is resistance-type heating rod.