CN101458193A - Shaft center compressive strength test method for concrete porous brick masonry - Google Patents

Abstract

The invention relates to an axial compressive strength test method of a concrete perforated brick masonry. The method is characterized in that: (1) an axial compressive strength test of the concrete perforated brick masonry is completed by a 2000kN compression testing machine; (2) the top of a test piece is leveled by cement mortar with the proportion of 1:3, and a leveling layer has a thickness of about 10mm; (3) a level ruler is used for checking flatness of the mortar after leveling to ensure uniform compression on the masonry during loading; and (4) a test admission mode is hierarchical loading, each level of load is 50kN, and the load between two levels of load is kept for 5 minutes during which the generation and development of a crack is observed. The invention provides the axial compressive strength test method of the concrete perforated brick masonry with simple test method, low cost and accurate result.

Description

Shaft center compressive strength test method for concrete porous brick masonry

Technical field

The present invention relates to Strength Testing Methods, especially a kind of shaft center compressive strength test method for concrete porous brick masonry.

Background technology

Green, energy-saving and environmental protection, sustainable development are the developing direction of building field.Clay brick damages and ploughs, the energy consumption height, forbidden by country, but masonry structure still has the space of its survival and development as a kind of traditional structure form of Building Trade in China.The substitute products of research and development clay brick are the present problems that faces of building trade.Concrete perforated brick is a steamed lime-sand brick, promptly utilizes trade wastes such as stone field mine tailings, flyash to add an amount of cement and processes, and be the energy-conserving product of a kind of green, environmental protection.Concrete perforated brick belongs to non-sintered steamed brick, is used for nonweight-bearing interstitital texture more; The purpose of this test is exactly the concrete porous brick masonry test by system, sums up its mechanical property of masonry, failure law and feature, for concrete perforated brick bearing masonry structural design and construction provide test basis.The concrete perforated brick physical dimension specification that test is adopted is 240mm * 115mm * 90mm, and material character and manufacture craft are similar to normal concrete small hollow block, and the hole rate is about 32%, and open-cellular form is the half-blindness hole, the about 1444kg/m3 of unit weight.Test specimen comprises 6 groups 30 of shaft center compression resistant test specimens altogether, 8 groups 48 of two-sided shearing resistance test specimens, 8 groups 56 of resisting bending tension (along slot with along straight joint) test specimens, test specimen use brick and mortar situation referring to table one, and the form of building by laying bricks or stones is with reference to the requirement of " Standard for test methods of basic mechincal properties of masonry " codes and standards.Hole faced down when test specimen was built by laying bricks or stones, paved mortar at the blind hole face, and guaranteed that the interlayer mortar builds plumpness by laying bricks or stones more than 90%, and upright seam full degree of mortar at bed joint is more than 85%, entered that the mortar height is no less than 6mm in the brick hole.Compare with the unselected clay fired brick, this hole brick water-intake rate is lower, and after building by laying bricks or stones, the masonry strength ascending velocity is slow, and therefore, test specimen is built by laying bricks or stones to finish and should be suppressed four skin bricks immediately at its top.Between curing period, it is relevant with environment temperature that test specimen reaches just the intensity time, and temperature is more than 20 ℃ the time, can reach early strength after about 24 hours, and when temperature was 5～10 ℃, need just can reach early strength in 48 hours approximately.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, provide a kind of test method simple, cost is low, and the result is shaft center compressive strength test method for concrete porous brick masonry accurately.

A kind of shaft center compressive strength test method for concrete porous brick masonry is characterized in that:

(1) test of concrete porous brick masonry axial compressive strength is finished in the 2000kN pressure testing machine;

(2) 1:3 cement mortar screeding, the about 10mm of screed-coat are adopted in the test specimen top;

(3) mortar utilizes surveyor's staff to check its flatness after floating, masonry uniform-compression when guaranteeing to load;

(4) test admission mode is a hierarchical loading, every grade of load 50kN, and two-stage was held lotus 5 minutes between loading, and held generation and the development of observing the masonry crack during the lotus.

Advantage of the present invention and beneficial effect are:

1. it is very accurate that this shaft center compressive strength test method for concrete porous brick masonry can make concrete porous brick masonry axial compressive strength test findings, can access the concrete porous brick masonry crack occurs later, the cracking of building body load is about 80%～90% of limit failing load, and first crack has more existing in the monolithic brick of upper and lower two end faces of masonry.

This shaft center compressive strength test method for concrete porous brick masonry with the increase concrete porous brick masonry of load rapidly to the development of masonry middle part, extend rapidly in the crack up and down, width increases, and be linked to be straight joint, and masonry loses load-bearing capacity and destroys, and masonry shows more obvious fragility feature.

3. find that also even load no longer increased after the crack appearred in masonry, the crack also can slowly be developed in the test of this shaft center compressive strength test method for concrete porous brick masonry, but the load-bearing capacity of masonry still has a small amount of increase at this moment.During the masonry compression damage, concrete perforated brick many places occur along hole and comes off.When brick and mortar strength were low, the crack occurred early, and the ratio of cracking load and limit failing load decreases.

4. this shaft center compressive strength test method for concrete porous brick masonry provides a kind of test method simple, and cost is low, and the result is shaft center compressive strength test method for concrete porous brick masonry accurately.

Embodiment

The invention will be further described below by specific embodiment, and following examples are descriptive, is not determinate, can not limit protection scope of the present invention with this.

This shaft center compressive strength test method for concrete porous brick masonry, wherein this method comprises the steps:

(1) test of concrete porous brick masonry axial compressive strength is finished in the 2000kN pressure testing machine;

(2) 1:3 cement mortar screeding, the about 10mm of screed-coat are adopted in the test specimen top;

(3) mortar utilizes surveyor's staff to check its flatness after floating, masonry uniform-compression when guaranteeing to load;

(4) test admission mode is a hierarchical loading, every grade of load 50kN, and two-stage was held lotus 5 minutes between loading, and held generation and the development of observing the masonry crack during the lotus.

Claims (1)

1. shaft center compressive strength test method for concrete porous brick masonry is characterized in that:

(1) test of concrete porous brick masonry axial compressive strength is finished in the 2000kN pressure testing machine;

(2) 1:3 cement mortar screeding, the about 10mm of screed-coat are adopted in the test specimen top;

(3) mortar utilizes surveyor's staff to check its flatness after floating, masonry uniform-compression when guaranteeing to load;

(4) test admission mode is a hierarchical loading, every grade of load 50kN, and two-stage was held lotus 5 minutes between loading, and held generation and the development of observing the masonry crack during the lotus.