Development and Evaluation Of Cement Grouted Bituminous Mix For Pavement Applications

Abstract

With the augmentation urbanization, the traffic has increased extensively on the urban roads of India. The extensive loading causes rutting and fatigue distress trouble inside the pavements which leads to pavement damage and reduce design life. Moreover, the pavement should full fill the performance and riding quality. The conventional design of pavements needs to be rationalized, to overcome further on challenges. The study finds a solution by investigating and exploring innovative pavement design and its performance parameter. The new-fangled plan to design semi-flexible pavement, which have property of flexible and rigid pavement both. The repetitive loading on flexible pavement causes fatigue distresses and potholes on surface, whereas the rigid pavement procure heavy cost while construction and riding quality problem due to the numerous joint. The study to solve the above mentioned problem has derived an amalgamation of flexible and rigid pavement properties called Cement Grouted Bituminous Mix design (CGBM). CGBM have unique property of crystalline lattice network of bitumen and cementitious material which makes strong bond inside the network. Several earlier studies showed its efficiency on the roads, but the experimental analysis performance for the Indian conditions was not performed which are essential in understanding the performance evaluation of cement grouted bituminous mix. The main focus of this study was to characterize several CGBM samples for different variants to analyze and characterize the design mix and performance. The aggregate gradation of the CGBM was done based on the MS2 guidelines of open graded bituminous mix. Specification of open graded surface mix is of Georgia ½’ PEM, with nominal size if aggregate 12.5 mm. The selected gradation had coarser aggregate so as to endow with higher air voids content in the mix. The gradation helped to achieve the air void content of 25-30% in the design mix of open graded bituminous mix. The open graded bituminous mixes are typically simple mixtures, often designed using only one aggregate size and with pre-determined binder content, usually in the range of 1.5 to 3.0% by weight of the total mix. The study emphasized the aggregate should not be soft as to degrade significantly during production, creating fines that will fill the voids necessary for proper grouting. The open graded mix been the combination of large NMAS and lower binder content makes these one of the most cost effective mix type. The cementitious grout material was formulated based on past research done to increase the performance validation of high performance cement paste as a grouting material for semi-flexible pavement. The requirement of grout material is to provide full depth grouting inside the open graded bituminous mix and strength for formulation performances. The grout material is evaluated on flowability and strength criteria. The CGBM sample were laboratory evaluated based on the indirect tensile strength, stability, modulus of elasticity and performance evaluation with the help of Cantabro test. The CGBM samples were compared with conventional BC course. The results showed enhanced and superior values of CGBM specimen as compared to conventional surface mix. IITPAVE was used to design the crust consisting of CGBM composition.