Yunnan Baoshan Volcanic Quality Powder On The Performance Impact Of Cement-based Materials Research

With the rapid development of railways, highways and other large-scale infrastructure in China, the builders had to consider that the supply situation of raw materials along the projects which could fit for engineering design requirements become one of the important issue. Yunnan Province is located in border area in China, lack of raw materials during the railway construction, especially Fly ash and other mineral admixtures used in short supply which can significantly improve the performance of concrete project, while other notable local characteristics of raw material resources (such as pozzolana material) related research base is obviously insufficient. In this paper, against this major practical problems and combination of volcanic ash (rock) in Yunnan is resources-rich and their use of technology status, field research was did to Yunnan Baoshan area on a large number of volcanic (tuff, pumice), started a systematic study with the basic properties of the volcanic ash and the performance of its cement-based materials after the comminutions process.The paper is based on related literature researches, used the macro-and micro analysis,detection methods and by means of laboratory tests, first of all analyzed the powder's chemical composition, volcanic activity, particle size and other physical and chemical properties; secondly investigated the influence rule of cement hydration process when volcanic powder mixed in cement, and then studied the rule of the doped volcanic paste, mortar, and fluidity and strength of low intensity volcanic powder concrete; thirdly, analyzed that the strength effect of volcanic powder in mortar and concrete system; finally comparatively studied the influence of resistant to sulfate attack when the volcanic powder was mixed in cement mortar and concrete. The results show that: (1) volcanic powder's chemical composition is mainly SiO2 and Al2O3, this two kinds of minerals in which are about 80% or more, SiO2 content in which is about 60%, CaO is about 7%, MgO,SO3 content is in lower levels, and chemical composition is good in Yunnan Baoshan area; (2) When volcanic powder particle size 80μm square mesh sieve is not more than 5%, it has no significant adverse effects to the water demand of cement system, the volcanic activity can up to 70% in 28d age, and could reduce the heat of cement system, when the fineness of the volcanic powder increased appropriately, it can improve the system workability and to fully play of the volcanic activity; (3) The early strength of the volcanic powder mortar and concrete are below the control samples, however in the late with the volcanic activity into full play, the strength increase gradually and higher than the control samples later; (4) Volcanic powder obtained from grounded the Yunnan Baoshan area's tuff that can helpfully improved the sulfate resistant of cement-based materials'.