Modified RCC Performance Research And Application In Rural Road

Traditional roller compacted concrete has the advantages of low cement content, small shrinkage, fast construction progress, and the disadvantages of insufficient compressive strength, producing cracks easily and poor toughness of faults. The concrete modification is applied to improve its performance defects in this paper. Based on Chongqing rural highway traffic conditions and geological conditions, the systematically research of the modified RCC is done in this paper. Through the experiment indoor and analysis of ANSYS finite element software, the following main research results are gotten.①The modified RCC mix design is obtained by the orthogonal experiment method. And on this basis, through testing the compressive strength, flexural strength and compressive modulus of elasticity of the modification of roller compacted concrete with different proportion of modifying agent and fiber in it, it is obtained that the mechanical properties of the RCC markedly improved through the fiber and the modifier agent solution mixed, and enhance effect increases with the increase of dosage. Considering economic benefit and modification of roller compacted concrete road performance, it is determined that the suitable dosage of modifier solution is 2 kg/m3, fiber content is 4 kg/m3.②To improve the modified RCC economic benefit, fly ash will incorporate modified RCC in excessive replacement method. Through the strength contrast between the roller compacted concrete that mixed without fly ash and that mixed with fly ash, it is obtained that compressive strength drop about 2%, the flexural strength increases by about 4.9%, strength basically keeps consistent roller compacted concrete without fly ash mixed according to excessive replacement method of adding fly ash. Therefore, it can be mixed with fly ash in the modification of roller compacted concrete in order to reduce cost.③The strength of RCC on the modification of different age were compared in this papers, modified RCC 7 d, 28 d compressive strength can reach 71% and 87% of the 90 d; 7 d, 28 d flexural strength can reach 87% and 95% of the 90 d. It is known that traffic can be open after modified RCC maintained around 4d, compared with ordinary concrete it has the advantages of short curing time, early traffic opening.④Based on indoor experimental data, the effect on pavement load stress and temperature stress of roller compacted concrete of different computing parameters are analyzed by ANSYS to obtain the regression formula for calculating load stress and temperature stress. On this basis, the present situation of chongqing rural highway subgrade and traffic volume are gathered with to calculate the modified RCC chongqing rural highway pavement typical structure.⑤Combined with “the technology for construction of highway cement concrete pavement ”, rural road roller compacted concrete pavement construction technology are introduced from the roller compacted concrete mixing and transportation, paving and rolling, surface joint, etc. And put forward the roller compacted concrete pavement construction quality inspection and control.