Study to Assess the Behaviour of Cement Grouted Bituminous Mix Prepared Using Pozzolanic Grouting Material

Cement grouted bituminous mix (CGBM) is a composite mixture where cementitious grout slurry is penetrated within the air voids of an Open-graded bituminous mix (OGBM). The CGBM surface has both flexible and rigid pavement merits and is considered a semi-flexible pavement type. Further, the choice of cold mix layer of CGBM also minimises the challenges associated with conventional hot mix types. In the present study, cementitious grout slurry is prepared using cement, fly ash, silica fume, and polycarboxylic ether-based superplasticiser to make the CGBM samples. To study the effect of grouting, the prepared CGBM samples were tested in the laboratory at 1, 3, 7 and 28 days after the curing period. Compressive strength, Marshall stability, indirect tensile strength, and resistance against the CGBM mix's moisture damage, improve with the increase in the curing period. CGBM mixes are less temperature susceptible and exhibit better resistance against moisture damage and abrasion loss. A trial section is constructed as per the design developed in the laboratory. The paved CGBM surface's field performance reveals that grout material is significantly improving the CGBM mix's behaviour. The evaluation of CGBM is considerably beyond the defined criterion in the Indian standards code, i.e. MoRTH (Ministry of Road Transport and Highways) fifth revision. Results and analysis presented in this manuscript may help the engineers to analyse the CGBM layer further.