CN205981857U - Semi rigid base course material shrinkage fracture capability test device - Google Patents

Abstract

The utility model relates to a device for testing the shrinkage and cracking performance of a semi-rigid base material. The device comprises an environment test box and a control box connected with the environment test box. One side of the environmental test chamber is provided with a heat-insulating side-hung door, and a group of movable guide rails are arranged symmetrically on the top and bottom of the interior, and push-pull handles are connected between the group of movable guide rails; There are two baffles on the guide rail, and a suspension wheel connected with the push-pull handle and with a cylindrical metal head I is arranged between the two baffles; the bottom of the suspension wheel is connected with a belt through a regular hexagonal screw sleeve. The upper chuck of the cylindrical metal head II; the lower chuck is provided on the movable guide rail at the bottom of the environmental test chamber; the concrete specimen with a seam is arranged between the upper chuck and the lower chuck . The utility model has the advantages of simple operation, convenient and rapid testing, and can directly evaluate the shrinkage performance of the material and the resistance strength to shrinkage and cracking through the breaking temperature, humidity and breaking strength.

Description

A test device for shrinkage cracking performance of semi-rigid base material

technical field

The utility model relates to the field of road material testing, in particular to a shrinkage cracking performance testing device for semi-rigid base material.

Background technique

The semi-rigid base material is easy to obtain and low in price. After being used for base construction, it has high rigidity, good stability, and high bearing capacity. It can well disperse the load transmitted by the surface layer and provide stable support for the surface layer. And it greatly reduces the bottom bending tensile stress and fatigue of the surface layer. Therefore, it has been the main base structure type of my country's expressways in the past few decades. With the development of our country's economy, the traffic volume of expressways has increased rapidly, and the pavement diseases of previously designed and constructed expressways have begun to increase, and the main type of diseases is reflective cracks. Since the semi-rigid base material is greatly affected by temperature and humidity, it is prone to fatigue cracks under the action of high and low temperature and dry-wet reciprocation. Pavement service life and service performance.

How to evaluate the temperature shrinkage and dry shrinkage cracking resistance of semi-rigid base materials is of great significance for guiding the durability design of raw materials and pavement structures. At present, the evaluation method for the crack resistance of semi-rigid base materials in my country is mainly through the two indicators of temperature shrinkage coefficient and dry shrinkage coefficient. These two indicators mainly reflect the volume shrinkage characteristics of the material, and cannot directly measure the crack resistance potential of the semi-rigid base material, so they are indirect evaluations.

Utility model content

The technical problem to be solved by the utility model is to provide a shrinkage cracking performance test device for semi-rigid base material with simple operation, convenient and quick test.

In order to solve the above problems, a semi-rigid base material shrinkage cracking performance testing device described in the utility model is characterized in that: the device includes an environmental test chamber and a control box connected with the environmental test chamber; the environmental test chamber There is a heat-insulated side-hinged door on one side, and a set of movable guide rails is symmetrically arranged on the top and bottom of the inner part, and a push-pull handle is connected between the set of movable guide rails; there are two movable guide rails on the top of the environmental test chamber. A baffle, between the two baffles is a hanging wheel connected with the push-pull handle and with a cylindrical metal head I; the bottom of the hanging wheel is connected with a cylindrical metal head II through a regular hexagonal screw sleeve The upper chuck; the movable guide rail at the bottom of the environmental test chamber is provided with a lower chuck; a concrete specimen with a seam is arranged between the upper chuck and the lower chuck.

A temperature sensor and a humidity sensor are arranged in the environmental test box, and the temperature sensor and the humidity sensor are respectively connected with the control box.

A handle and a transparent glass window are respectively arranged on the heat-insulating side-hung door.

Both ends of the upper chuck and the lower chuck are provided with annular circular holes, and anchor rods passing through the concrete specimen with seams are arranged between the annular circular holes at the ends of the two sides; The anchor rods are respectively connected with the upper chuck and the lower chuck through nuts.

The anchor rod is located at the center position in the width direction of 100 mm from the upper and lower ends of the concrete specimen with slots.

A tensile and compressive dynamometer is provided between the lower chuck and the movable guide rail at the bottom of the environmental test chamber.

Both the cylindrical metal head I and the cylindrical metal head II are provided with threads matching the regular hexagonal screw sleeve.

Compared with the prior art, the utility model has the following advantages:

1. The utility model is equipped with a dual-purpose dynamometer for tension and compression. When the trabecular specimen of the semi-rigid base material breaks and fails, the dynamometer can read and record the critical tension value.

2. In the utility model, the push-pull handle and the upper and lower chucks of the test piece slide synchronously on the movable guide rail, and the test piece can be pulled out of the door through the push-pull handle, which is convenient for loading and unloading of the test piece.

3. The utility model is equipped with a regular hexagonal screw sleeve, so the height of the chuck on the test piece can be adjusted, and at the same time, prestress is applied to the test piece after the test piece is installed.

4. The utility model is simple to operate, convenient and quick to test, and can directly evaluate the shrinkage performance of the material and the resistance to shrinkage and cracking through the breaking temperature, humidity and breaking strength, making it different from the indirect evaluation of the material by the temperature shrinkage coefficient and dry shrinkage coefficient Shrinkage cracking performance is suitable for testing the shrinkage cracking performance of semi-rigid base materials in the road field, including dry shrinkage cracking and temperature shrinkage cracking, such as cement stabilized base materials, fly ash stabilized base materials, etc.

Description of drawings

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described in further detail.

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic diagram of loading when the trabecular specimen of the utility model is tested.

Fig. 3 is a schematic diagram of the middle and upper collets of the present invention.

Fig. 4 is a schematic diagram of the middle and lower chucks of the present invention.

Fig. 5 is a sectional view of a regular hexagonal screw sleeve in the utility model.

In the figure: 1—environmental test chamber, 2—heat-insulated side-hung door, 3—handle, 4—transparent glass window, 5—hanging wheel, 6—push-pull handle, 7—regular hexagonal screw sleeve, 8—upper chuck , 9—concrete specimen with seam, 10—lower chuck, 11—tension and compression dynamometer, 12—anchor rod, 13—movable guide rail, 14—baffle plate.

detailed description

As shown in Figures 1 to 5, a semi-rigid base material shrinkage cracking performance test device, the device includes an environmental test chamber 1 and a control box connected to the environmental test chamber 1.

One side of the environmental test chamber 1 is provided with a heat-insulating side-hung door 2, and a group of movable guide rails 13 are arranged symmetrically on the top and bottom of it, and a push-pull handle 6 is connected between the group of movable guide rails 13; There are two baffles 14 on the guide rail 13, and a hanging wheel 5 connected with the push-pull handle 6 and with a cylindrical metal head I is arranged between the two baffles 14; the bottom of the hanging wheel 5 passes through the regular hexagonal screw sleeve 7 There is an upper chuck 8 with a cylindrical metal head II; a lower chuck 10 is provided on the movable guide rail 13 at the bottom of the environmental test chamber 1; Item 9.

Wherein: the environment test box 1 is provided with a temperature sensor and a humidity sensor, and the temperature sensor and the humidity sensor are respectively connected with the control box.

A handle 3 and a transparent glass window 4 are respectively provided on the heat-insulating side-hung door 2 .

The ends on both sides of the upper chuck 8 and the lower chuck 10 are provided with annular holes, and between the annular holes at the ends of the two ends are provided with anchor rods 12 passing through the concrete specimen 9 with seams; the anchor rods 12 are respectively connected with the upper chuck 8 and the lower chuck 10 by nuts.

The anchor rod 12 is located at the central position in the width direction of 100 mm from the upper end and the lower end of the concrete specimen 9 with a slit.

Between the lower chuck 10 and the movable guide rail 13 at the bottom of the environmental test chamber 1, a dual-purpose dynamometer 11 for tension and compression is provided.

Both the cylindrical metal head I and the cylindrical metal head II are provided with threads matching the regular hexagonal screw sleeve 7 .

Embodiment The test specimen is a 400mm×100mm×100mm concrete specimen 9, and the evaluation indexes are fracture temperature, humidity and fracture strength.

In the first step, according to the JTG_E51-2009 Highway Engineering Inorganic Binder Stable Material Test Procedure T0844-2009 method, the material to be tested is formed into a concrete specimen 9 of 400mm×100mm×100mm, and placed in a standard curing room for curing until the age of 28 days;

In the second step, cut a crack with a depth of 20 mm at the middle position of the cured concrete specimen 9 in the length direction, and drill holes at a center position 50 mm away from the end in the length direction;

The third step is to open the heat-insulating side-hung door 2 of the test, pull the upper clamp 8 and the lower clamp 10 of the specimen out of the door by pushing the handle 6, and first use the anchor rod 12 to pass through the ring at the end of the lower clamp 10 at the same time. The drilling of the circular hole and the test piece, and fix the end of the anchor rod 12 with a nut, so that the installation of the test piece on the lower chuck 10 is completed;

The fourth step is to adjust the height of the upper chuck 8 by turning the regular hexagonal screw sleeve 7, align the drilled hole of the test piece with the circular hole at the end of the upper chuck 8, and fix the test piece on the upper chuck in the same way 8, turn the regular hexagonal screw sleeve 7 again, raise the upper chuck 8, and stop when the pull-compression dual-purpose dynamometer 11 shows a tensile force of 500N, then push the test piece into the center of the environmental test chamber 1, and use the baffle 14 fix the position of suspension wheel 5 on movable guide rail 13.

The fifth step is to close the heat-insulated side-hung door 2, fix one variable in the temperature and humidity, and gradually change the other variable through the environmental test chamber 1 until the specimen breaks, and record the temperature, humidity and tension and compression of the specimen when it breaks. Use the reading when the test piece breaks on the dynamometer 11.

Claims (7)

1. A semi-rigid base material shrinkage cracking performance testing device, characterized in that: the device includes an environmental test chamber (1) and a control box connected to the environmental test chamber (1); the environmental test chamber (1) There is a heat-insulated side-hung door (2) on one side, and a set of movable guide rails (13) are arranged symmetrically on the inner top and bottom, and push-pull handles (6) are connected between the set of movable guide rails (13); the environmental test There are two baffles (14) on the movable guide rail (13) at the top of the box (1), between the two baffles (14) there is a cylindrical The hanging wheel (5) of the metal head I; the bottom of the hanging wheel (5) is connected with the upper chuck (8) with the cylindrical metal head II through the regular hexagonal screw sleeve (7); the environmental test chamber ( 1) The movable guide rail (13) at the bottom is provided with a lower chuck (10); between the upper chuck (8) and the lower chuck (10) is a concrete specimen with a seam ( 9). 2. A semi-rigid base material shrinkage cracking performance testing device as claimed in claim 1, characterized in that: the environmental test chamber (1) is equipped with a temperature sensor and a humidity sensor, and the temperature sensor and the humidity sensor are respectively connected with The control box is connected. 3. The device for testing the shrinkage and cracking performance of semi-rigid base material according to claim 1, characterized in that: the heat-insulating side-hung door (2) is respectively provided with a handle (3) and a transparent glass window (4). 4. A device for testing the shrinkage cracking performance of semi-rigid base materials according to claim 1, characterized in that: both ends of the upper chuck (8) and the lower chuck (10) are provided with ring-shaped A round hole, the anchor rod (12) passing through the concrete specimen (9) with a slot is arranged between the annular round holes at the ends of the two sides; the anchor rod (12) is respectively connected to the The upper chuck (8) is connected to the lower chuck (10). 5. A semi-rigid base material shrinkage cracking performance test device according to claim 4, characterized in that: the anchor rod (12) is at a distance from the upper and lower ends of the concrete specimen (9) with seams The center position in the width direction at 100mm. 6. A semi-rigid base material shrinkage cracking performance test device according to claim 1, characterized in that: said lower chuck (10) and said movable guide rail (13) at the bottom of said environmental test chamber (1) ) is provided with a dual-purpose dynamometer (11) for tension and compression. 7. A semi-rigid base material shrinkage cracking performance testing device as claimed in claim 1, characterized in that: the cylindrical metal head I and the cylindrical metal head II are equipped with the regular hexagonal Matching thread of the screw sleeve (7).