## 1 Introduction  
New methods and materials for repairing old or damaged pavement are necessary given the increasing demand placed on roadway infrastructure [1; 2; 3; 4; 5; 6]. Road repairs require rapid reopening after a short-term period of blocking traffic to minimize traffic congestion [7; 8; 9; 10; 11]. Typically, rapid-hardening cement concrete is used for this purpose [12; 13]. During the hardening process, hydration heat is generated when the compounds in the cement form chemical bonds with water [1; 2; 3; 6; 12]. Thus, hydration is required for hardening/curing [1; 2; 3; 6; 12]. Early strength is achieved by enhancing the movement of heat and moisture inside the concrete pavement structure for rapid hardening [6; 12]. However, under the conditions of the actual site, the movement of heat and moisture is restricted, internally and externally, causing tensile stress in the concrete and ultimately, fine crack formation [6; 12]. Fine cracks allow water to penetrate the concrete pavement, leading to defect formation, loss of original function and other problems requiring near-term future repairs [4; 6; 7]. Latex is added to rapid-hardening cement to improve its workability and durability [13; 14]. The viscosity of latex helps to prevent separation of materials. Thus, it increases the flexural strength and tensile force/formability of concrete [12; 13; 14]. This occurs due to the surfactant interactions with the latex components [5; 10; 11]. The formation of a latex film improves the bond strength and mechanical properties of the concrete, while increasing the concrete's resistance to water permeability [5; 10; 11]. Other advantages of adding latex to concrete include improved viscosity, water tightness, freezing and thawing resistance in addition to anti-abrasion and anti-chemical resistance [10; 11; 12; 13; 14]. However, despite the excellent workability and durability of latex-modified rapid-set cement concrete, it still has the same problems associated with rapid-set cement [10; 11; 12; 15]. The addition of latex to concrete tends to delay the onset of the targeted initial strength [12; 15]. Therefore, a large amount of rapid set cement should be used. In particular, the use of a large amount of rapid set cement for securing initial strength produces hydration heat, resulting in crack formation due to shrinkage/contraction, temperature variation and restraints inside the concrete [6; 12; 13; 15]. The occurrence of these cracks reduces the time between subsequent re-pavement maintenance due to a deterioration in pavement durability with water permeability [10; 11; 12; 13]. Thus, with massive use of ultra-rapid hardening cement, it is important to find the means to minimize or prevent hydration-heat crack formation to improve the durability of concrete and in turn, reduce the time and cost involved by deferring the requirement for re-pavement [12; 13; 15]. In this research, crack formation was controlled by the use of reinforced fibers. The addition of reinforcing fibers minimized concrete crack formation by dispersing the fibers in random directions throughout the concrete [16; 17; 18; 19; 20; 21; 22; 23]. Additionally, the dispersion of the reinforcing fibers improved the brittle and ductile properties of the concrete by inhibiting crack formation and growth [17; 18; 19; 20]. Fiber-reinforced concrete (FRC) is concrete that contains or is reinforced with dispersed, randomly-oriented and unconnected fibers [16]. Concrete is indigenously brittle, but if reinforced with fibers within its structure, such brittleness is rectified and its ductile property is improved due to the suppression of crack growth by the reinforced fibers [17; 18; 19; 20; 21]. Furthermore, in the method of suppressing the occurrence of cracks, the water-cement ratio is lowered to reduce the amount of water used [22; 23]. The roller compaction concrete is applied in this study in terms of construction. Roller compaction concrete can be installed at a low water-cement ratio and can suppress shrinkage cracks caused by water evaporation.