CN207764049U

CN207764049U - A kind of experimental rig for evaluating concrete performance

Info

Publication number: CN207764049U
Application number: CN201820165722.6U
Authority: CN
Inventors: 朱涵; 邵建文; 陈龙龙; 石万万; 李宏亮
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2018-01-31
Filing date: 2018-01-31
Publication date: 2018-08-24
Anticipated expiration: 2028-01-31

Abstract

The utility model discloses a kind of experimental rigs for evaluating concrete performance, the device includes the bottom plate and rectangle mould that thickness is 3mm, the rectangle mould is parallelogram sturcutre, and it is inter-connected via a bolt joint by the steel plate that two pieces of bending angles are 120 °, rectangle mould is inter-connected via a bolt joint with bottom plate, and the bottom plate both ends are connected with portable holder by welding manner.The material property that the utility model is intended to science, conveniently, accurately with specification studies concrete under complex stress condition.For example, there are three types of the cement concrete of match ratio, its best, worst and general concrete material in the case where bearing pressure, stretch bending and shearing action can be obtained using the device.

Description

A kind of experimental rig for evaluating concrete performance

Technical field

The utility model is related to construction material, field of civil engineering, and in particular to one kind is for evaluating complex stress condition The experimental rig of lower concrete performance.

Background technology

Intensity is the important test index of concrete, but with the fast development of concrete admixture and admixture, especially For high performance concrete, reflect that the performance of concrete seems that some are thin and unilateral with traditional compression strength.State The inside and outside concrete test research carried out under a large amount of lists, multiaxial compression state, test specimen used is using perfect condition as standard, tool There is height geometrical symmetry, the stress field generated is also such.

Many large-sized concrete complex components are typically in two-way or triaxial stress state, only use uniaxial tensile compression test not It can reflect the characteristics of strength and deformation in practical structures under multiaxis complex stress condition completely, therefore, how explore in test The concrete test device for going out under a kind of low-symmetry or asymmetry complex stress condition all the time all pay close attention to by remarks.

Therefore, there is an urgent need for a kind of for evaluating the novel test device of concrete performance and side under complex stress condition at present Method is so that it can more comprehensively reflect the material property of practical structures, and observation is facilitated to destroy crack.

Utility model content

The purpose of this utility model is to overcome deficiencies in the prior art, provide a kind of for evaluating concrete performance Experimental rig, it is intended to science, the material property for conveniently, accurately with specification studying concrete under complex stress condition.For example, There are three types of the cement concretes of match ratio, can obtain it in the case where bearing pressure, stretch bending and shearing action most using the mold Good, worst and general concrete material.

The purpose of this utility model is achieved through the following technical solutions：

A kind of experimental rig for evaluating concrete performance, including thickness is the bottom plate and rectangle mould of 3mm, institute It is parallelogram sturcutre to state rectangle mould, and by two pieces of bending angles for 120 ° of steel plate is inter-connected via a bolt joint and At rectangle mould is inter-connected via a bolt joint with bottom plate, and the bottom plate both ends are connected with portable holder by welding manner.

Preferably, the length of the bottom plate and wide respectively 300mm and 180mm.

Preferably, the length of side of the rectangle mould is 150mm.

Preferably, the length of the portable holder and wide respectively 100mm and 25mm.

Compared with prior art, advantageous effect caused by the technical solution of the utility model is：

(1) cube specimen in traditional experiment generates major cracks along any one diagonal and destroys, and destroys Direction have uncertainty, and obtained by the utility model experimental provision trapezoid body concrete compression when follow Tresca bend Criterion is taken, the node near obtuse angle diagonal line is first surrendered, and the destruction crack of test specimen is substantially along obtuse angle diagonal, and failure mechanics are only There are one and can predict.

(2) the utility model is being tested by trapezoid body concrete anti-compression so that test specimen is in pressure, stretch bending and cuts simultaneously It under force effect, is tested compared to traditional concrete anti-compression, can be very good the comprehensive of concrete material under reflection complex stress condition Close performance.To a certain extent, it can be said that trapezoid body is bigger with the ratio of cube strength, illustrate the anti-of concrete Better performances are pressed, and tension is curved and shear resistance is slightly worse；Ratio is small, then illustrates that the stretch bending of concrete and shear resistance are preferable, and Anti-pressure ability is poor.

Description of the drawings

Fig. 1 is the size and structural schematic diagram for the experimental rig that the utility model is used to evaluate concrete performance.

Fig. 2 be in Fig. 1 A-A to section size and structural schematic diagram, unit be mm.

Fig. 3 is the section size and structural schematic diagram of B-B direction in Fig. 1, and unit is mm.

Fig. 4-1 and Fig. 4-2 is the structural schematic diagram of square concrete model and trapezoid body concrete model respectively.

Fig. 5-1 is square concrete model result of calculation τ_maxSize, direction schematic diagram.

Fig. 5-2 tilts 30 ° of trapezoid body concrete model result of calculation τ_maxSize, direction schematic diagram.

Reference numeral：1- bottom plates, the rectangles 2- mould, the portable holders of 3-, 4- bolts.

Specific implementation mode

The utility model will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1 to Figure 3, a kind of experimental rig for evaluating concrete performance, including thickness is the bottom plate of 3mm 1 and rectangle mould 2, rectangle mould 2 is parallelogram sturcutre, and passes through spiral shell by the steel plate that two pieces of bending angles are 120 ° Bolt 4 is connected with each other, inclination angle alpha=30 ° of the rectangle mould 2 of formation, and rectangle mould 2 is with bottom plate 1 also by spiral shell Bolt 4 is connected with each other, and 1 both ends of bottom plate are welded with portable holder 3.

It is as follows to choose the analytical procedure that the utility model experimental provision is tested：

ANSYS finite element analysis softwares are used first, according to Tresca yield criterions, (such as to square concrete model Shown in Fig. 4-1) and angle of inclination be respectively 2 °, 4 °, 6 °, 8 °, 10 °, 20 °, 30 ° 7 trapezoid body concrete model (such as Fig. 4- Shown in 2) carry out analysis calculating；In Fig. 4-1 and Fig. 4-2, α-angle of inclination；Bcos α-rake side the length of side (mm).

Then maximum is cut in the trapezoid body concrete model of comparative analysis square concrete model and differing tilt angles Stress τ_maxAnd its distribution situation；Fig. 5-1 show square concrete model result of calculation, and stress value shown in Fig. 5-1 is to expand Numerical value after big 1000 times, the maximum shear stress τ of each node in square concrete model_maxValue is 500；Virgule Represent τ at the node_maxTrue directions, be respectively 45 ° and -45 ° with horizontal axis angle.The trapezoid body concrete model of α=30 ° Result of calculation is as shown in Fig. 5-2, the τ of each nodes of Fig. 5-2_maxAlong obtuse angle diagonal line antisymmetry, lower left numerical value represents each node τ_maxValue, shown stress value is the numerical value expanded after 1000 times；Virgule represents τ at the node_maxTrue directions, upper right side Numerical value represents each node τ_maxWith the angle on trapezoid body rake side.Show the increasing with inclination angle alpha by result of finite element Greatly, in the body Model of rectangle many places node τ_maxIncreased and is increased along obtuse angle diagonal number of nodes.

Therefore the trapezoid body Mold Making concrete performance test device of inclination angle alpha=30 ° is selected；For ease of form removal, Using sectional die, see Fig. 1 to Fig. 3.

Specifically, using trapezoid body concrete crushing strength and cube concrete crushing strength as index, comparative analysis is mixed Rubber and performance of the concrete of rubber under complex stress condition is not mixed：

(1) match ratio of concrete is as shown in table 1, and cement is the Camel P.O42.5 ordinary silicons of Tianjin cement plant production Acid salt cement；Coarse aggregate is the broken pebble that particle size is 0.5~2cm, clay content<1%；Fine aggregate is nature medium sand, most Big grain size 5mm, continuous grading, fineness modulus 2.7；Rubber aggregate is 1~2mm rubber grains of Tianjin Ke Wei rubber plants production； Water-reducing agent is naphthalene water reducer, water-reducing rate 20%.Wherein A groups are common concrete proportioning, and B groups are to add 4% coagulation soil property The rubber aggregate of amount substitutes fine aggregate.

Table 1 tests match ratio (kg/m³)

Number	Cement	Sand	Stone	Water	Rubber aggregate	Additive
							A	500	420	1262	188	0	3.82
B	500	420	1262	188	40	3.82

(2) Mold Making trapezoid body concrete sample shown in Fig. 1 is used, A groups and B groups make 6 trapezoid body test specimens, and 6 A cube specimen.

(3) it mixes cement sill according to each match ratio, pours into mold, smoothed out after being plugged and pounded with tamper, test specimen is set In jolt ramming on plain bumper.

(4) molded test specimen is placed in standard curing room (20 ± 1 DEG C of temperature, 95% or more relative humidity) maintenance for 24 hours After remove die trial.

(5) test specimen is taken out to 7d, 28d age, carries out rectangle body concrete and is tested with cube concrete anti-compression.

(6) compression strength and ratio calculated of trapezoid body concrete sample and cube concrete sample, knot are measured respectively Fruit is as shown in Table 2,3.

2 ordinary concrete specimens intensity value of table

3 rubber concrete test piece intensity value of table

(7) contrast table 2 and table 3 as a result, common trapezoid body concrete sample and cube concrete sample compression strength Ratio is about 0.51, and after mixing rubber aggregate, ratio is about 0.44.

(8) it draws a conclusion：Although causing the compression strength of concrete to reduce after incorporation rubber aggregate, tension is curved and anti- Cut the opposite raising of ability.

The utility model is not limited to embodiments described above.Above the description of specific implementation mode is intended to describe With illustrate the technical solution of the utility model, the above mentioned embodiment is only schematical, is not restrictive. In the case of not departing from the utility model aims and scope of the claimed protection, those skilled in the art are in this practicality The specific transformation of many forms can be also made under novel enlightenment, these are belonged within the scope of protection of the utility model.

Claims

1. a kind of for evaluating the experimental rig of concrete performance, which is characterized in that including thickness be bottom plate and the rectangle of 3mm Mould, the rectangle mould are parallelogram sturcutre, and pass through bolt phase by the steel plate that two pieces of bending angles are 120 ° It connects, rectangle mould is inter-connected via a bolt joint with bottom plate, and the bottom plate both ends are connected with hand by welding manner Carry holder.

2. a kind of experimental rig for evaluating concrete performance according to claim 1, which is characterized in that the bottom plate Long and wide respectively 300mm and 180mm.

3. a kind of experimental rig for evaluating concrete performance according to claim 1, which is characterized in that the trapezoid body The length of side of mold is 150mm.

4. a kind of experimental rig for evaluating concrete performance according to claim 1, which is characterized in that the portable branch The length of frame and wide respectively 100mm and 25mm.