The novel cement grout asphalt composite (CGAC) in this study is a new semiflexible composite consisting of open-graded hot mix asphalt (HMA) filled by injecting cement grout materials. The mechanical performance and engineering properties of the composite were evaluated through laboratory tests, including the Marshall stability test, rutting test, three-point bending test, split tensile test, and permeability test. Moreover, field test sections were constructed, and the laboratory test results and in situ results were compared. The results showed that, after grouting, the performance of composite materials was further enhanced, especially their high-temperature stability and moisture sensitivity. In fact, no permanent deformation (rutting) occurred, and the tensile strength ratio (TSR) was increased by 18.7%. In situ test applications revealed that compared with manual grouting, mechanized grouting technology had positive influences on field constructability and performance of CGAC regarding Marshall stability and splitting tensile strength. Findings of this study are beneficial to design, construction technology, and pavement maintenance.

The cold recycled mixture has insufficient resistance to cracking, and the process of fracture is incompletely understood. This study used digital image correlation (DIC) technology and a semi-circular bending test to investigate the anti-crack performances and fracture propagation of basalt fiber-reinforced cold recycled mixture (BFCRM). The load-displacement, full-field strain, full-field displacement, displacement rate and crack propagation map were obtained to evaluate the BFCRM’s anti-crack performances. The control cold recycled mixture without fibers was also prepared for comparison. Meanwhile, the fracture process zone (FPZ) during loading were compared and quantitatively assessed by digital image correlation analyses, and the fiber distribution and microscopic features at fracture surface was observed by scanning electron microscopy. The results show that the formation of microcracks of BFCRM takes more time than that of the control group without fiber. Based on DIC observations, the basalt fibers maintain strong anti-crack performance in cold-recycled mixtures and reduce fracture damage. The fracture surface morphology also revealed that basalt fiber exhibited adsorption, bridging, anchoring, stability, and strengthening effects at micro/nano scale, which further improved anti-crack performance e and hindered crack development of cold recycled asphalt mixtures.