Preparation And Properties Of New Roadside Support Filling Material

At present, domestic and foreign roadside support filling materials are mainly high-water quick-setting materials and paste filling material. Bauxite was the main raw of high water materials. However, bauxite producers was very less and the price was high; Secondly, the unstable workability and the large different effects was restricting the promotion of high water materials.Roadside support paste filling material met the filling requirements and was able to process the necessary strength, while the main raw of material originated widely, low prices. Therefore, the research and development of the paste filling materials roadside was the future direction of technology development. The poor pumping capacity and support capacity of traditional filling material is not compatible to complexity of deep and high stress environment, which were the key technical problems and not yet been solved.The paper focuses on two aspects:one is to study the workability of new filling material for the application of roadside support technology, another is to study the mechanical properties of new filling material against with complex geological conditions in deep coal mining. This paper analyzed workability requirements of the roadside support filling material, resulting in the object and technical route of the filling materials research.The results show that:(1) Various factors on the roadside support the workability and mechanical properties of new filling material are taken into account in this paper. Optimum water-cement ratio, fly ash-cement ratio, Paste Aggregate ratio, sand ratio, the proportion of larger coarse aggregate size, CaCl2 content, air entraining agent content, Na2SO4 content were identified as 0.41-0.42,0.7-0.8,0.5-53,0.4-0.45,1/3-2/3, in the vicinity of 0.35,0.005%-0.01%,2%.(2) On the basis of meeting the requirements of the slump, the specimens almost can be stripping after 5 hours, except very small part of the specimens. The lowest level of 1d compressive strength of all specimens is basically more than 3MPa, the highest level is basically up to 5MPa.28d compressive strength is all reached 20MPa, some exceed 25MPa, even 30MPa.(3) The incorporation of fly ash can reduce the average elastic modulus of filling material specimen, but also significantly increase the deformation capacity of filling materials. At the same time, the filling material mixed with fly ash showed better stress-strain curves of yield stress characteristics, indicating that the filling material had a better yielding.Should be emphasized that the test results obtained under laboratory conditions, in practical engineering application process also requires continuous improvement and perfection of coal mining in order to facilitate the smooth filling support.