Study On The Durability Of Fiy Ash Roller Compacted Concrete

RCC(Roller Compacted Concrete) is high density and high strength dry Concreteby vibration rolling with technical and economic advantages,such as, saving cement,shrinkage, high strength, construction speed and traffic opening early.The study used fly ash admixture technology, and was mainly used in appliedresearch on RCC pavement. Test adopted fly ash to replace part of cement to reducethe amount of cement, in order to achieve the purpose of reducing construction costs,and fill the role of the replaced part using its fine aggregate; In addition, fly ash usedmostly for domestic solid industrial waste, and it was used with saving energy,protecting the environment,as the role of turning waste into treasure. Therefore, flyash was used in RCC, with a very significant technical, economic, environmentalbenefits.This paper first proposed the technical requirements of raw materials forFRCC(Fly Ash Roller Compacted Concrete) pavement and then presented mix designmethod for FRCC based on orthogonal design. By adopting orthogonal design methodit studied the workability and the compressive and flexural strength of FRCC andanalysed the influence on workability and mechanical properties of concrete by flyash. Meanwhile it also studied the impact resistance,the frost resistance,abrasionresistance,shrinkage and other road performance of FRCC. By the mix design,itpicked out a few groups FRCC mix with excellent workability. It proved that theFRCC pavement has excellent durability by evaluation of the durability.Based on a lot of research, indoor and outdoor experimental research foundationand theory, this paper had made the following key findings.①In accordance with rural RCC pavement with low volume traffic,reguirementsand specifications in accordance with cement, coarse aggregate, fine aggregate andother raw materials was proposed.In order to improve the modified VC value asworkability index and flexural strength as strength index,it researchs mechanicalproperties and durability of FRCC with orthogonal design.②With modern materials testing,This paper studied interface structure of flyash-cement hardened paste and FRCC,and analyzed mechanism that fly ash improvesdurability of RCC.③According to requirements of “the cement concrete pavement construction specifications”(JTG F30-2003), combined with RCC construction experience, themethods of the quality control of RCC raw materials was proposed, and described thevarious construction steps: mixing, transportation, paving, rolling, joints, curing andother aspects of the construction of technical measures.Quality control and solutionsof several key elements on RCC construction process were proposed.