Study On Mechanical And Thermal Properties Of Straw Fiber Powder Concrete Hollow Blocks

Straw fiber powder concrete hollow block refers to ordinary straw stalks after machining, made into different size of straw fiber powder, mixed with concrete by certain proportion, the formation of a straw fiber cement base composite concrete hollow block. This kind of plant fiber reinforced concrete and normal concrete, and compared to other types of fiber reinforced concrete with light quality, small density,good ductility, can effectively control the crack development and the advantages of excellent heat preservation and heat insulation effect, for the high speed development,seeking to energy conservation and environmental protection of China's construction industry, has a good application prospect.This article mainly through, straw fiber powder according to the size of the particle size distribution can be divided into four categories, respectively corresponding to A1,A2, A3, A4, and according to the cement weight 0%, 2%, 4%, 6%, 8%, 10% of the mixed with concrete, made into different levels, different size of straw fiber powder concrete hollow block, to study the straw fiber powder concrete and its basic physical properties of the hollow block, and straw fiber powder compressive strength of concrete standard test block and hollow block of compressive strength, flexural strength and heat resistance.Through the study found that, when adding straw fiber powder content exceeds10%, the initial and final setting time of concrete is far more than the initial and final setting time of conventional concrete. And after the straw fiber powder into the concrete,due to water absorption characteristics of straw fiber, leading to the workability of concrete is reduced, slump, water consumption increases at the same time.Through the analysis of the result of the compressive strength of standard test blocks, found that the value of the compressive strength of test blocks falling, but in some proportion of cases, the compressive strength value still meet the design strength.And straw fiber powder compressive strength of concrete hollow block, compared with the plain concrete hollow block, its compressive strength declined, especially under the A3, A4 size, fiber content exceeds 6%, strength decreased fastest, already cannot satisfy the use requirement. And straw fiber powder standard flexural strength of concrete hollow block, compared with the ordinary plain concrete hollow block is also reduced,but under A1, A2 size range, the content of no more than 4%, the flexural strength slightly, but the A3, A4 size under flexural strength drop more. Although on the mechanical properties, straw fiber powder concrete hollow block is reduced, but through the physical properties of block test found that straw fiber powder concrete hollow block small density, light quality, on the control of crack development, also has a good effect.Ratio and the same design of straw fiber powder concrete hollow block, through the principle of heat conduction in the test found that the thermal resistance changes basically met: under the same particle size, thermal resistance with the increase of the content increase, the effect is obvious; Under the same content, thermal resistance increases with the decrease of the particle size, relatively small changes. Visible, straw fiber powder concrete hollow block on the thermal performance, good, has a high practical value.Through test showed that straw fiber powder concrete hollow block in the mechanical properties decreased, but its heat preservation and heat insulation effect is good, and the light quality, can effectively control the crack development advantages, is China's construction industry for the development of green, environmental protection,energy saving, has a high research significance and value.