Concrete is a very popular construction material (its annual consumption is about 25 billion tons) because of its low cost, availability, long durability, easily given shape and size, and ability to be sustained in extreme weather conditions [1]. On the other hand, concrete has a number of problems that cause considerable concern in the construction industry. Concrete is a brittle material with low tensile strength (approximately 1/10 of its compressive strength) [2]. In addition to its low tensile strength, concrete fracture toughness is at least 100 times less than that of steel. Moreover, concrete elements have a low capacity for resisting cracks under dynamic loads [3]. Consequently, these factors allow concrete structures to easily grow cracks during service life, create access for deleterious agents, and ultimately lead to steel bar corrosion ^{[3][4][5][6][7][8]}[3,4,5,6,7,8]. Conventional concrete with low strength and a brittle nature creates concerning issues such as the durability and large section sizes of RC and prestressed structures ^{[9][10][11][12]}[9,10,11,12]. To overcome the limitations of conventional concrete, a new scope of research was created to develop a cementitious composite having ultrahigh compressive strength, low porosity, and high ductility. Substantial research has been carried out to develop this technology, and it is known as ultrahigh-performance fiber-reinforced concrete (UHPFRC).

The development of UHPFRC began as ultrahigh-strength cement pastes. In 1972, Yudenfreund et al. [13] and Roy et al. [14] first produced ultrahigh-strength cement pastes with low porosity. Yudenfreund et al. [13] achieved about 240 MPa of compressive strength, using 0.2 water to binder ratios at 25 °C. Roy et al. [14] applied (1) hot pressure (25 to 50 ksi pressure at nearly 100 °C) and (2) high pressure (100 ksi pressure) to the concrete mix, and it resulted in 59.3 and 46.1 ksi compressive strength, respectively. The development of UHPFRC reached advanced stages after the 1980s. Alford and Birchall [15] and Bache [16] used densified small particles (DSP) and macro defect-free (MDF) paste concepts to develop UHPFRC. In 1994, De Larrard and Sedran [17] applied a 0.14 water-to-binder proportion and packing-density concept to develop flowable cement–mortar composite pastes with 236 MPa of compressive strength. Lastly, Richard and Cheyrezy [18] introduced ultrahigh-strength ductile concrete designated as reactive-powder concrete (RPC), which was the forerunner of UHPFRC. Richard and Cheyrezy [18] demonstrated that ultrahigh strength and toughness could be achieved by optimizing granular materials, using the packing-density method, where the concrete mix was subjected to heat from 20 to 400 °C and pressure at 50 MPa. Maximal compressive strength of 810 MPa was obtained by incorporating 3% steel fibers. Following the successful production of UHPFRC under laboratory conditions, various researchers attempted to produce it without any distinguishing characteristics. Various researchers attempted to produce UHPFRC with special treatments such as heat curing, high pressure, and extensive vibration ^[19][20][21][19,20,21]. UHPFRC was recently successfully implemented in large-scale RC structures and for retrofitting structural elements such as beams, columns, and bridge piers ^{[22][23][24][25][26]}[22,23,24,25,26].

Other than having high strength, UHPFRC has a number of advantages, i.e., the dense matrix improves the durability of concrete ^[18][27][18,27]; for the same external load, it offers one-third or one-half the section size of conventional concrete [28], and it is more ecofriendly compared to traditional concrete, owing to fewer emissions of greenhouse gases ^{[29][30][31][32][33][34]}[29,30,31,32,33,34]. Even though UHPFRC has numerous advantages, its applications are very limited, owing to higher manufacturing costs than those of conventional concrete. Therefore, the application of UHPFRC with low production costs is a major challenge. There are a couple of methods that may reduce the manufacturing costs of UHPFRC: (1) decreasing or optimizing the percentage of steel fibers without deteriorating the mechanical properties ^[35][36][35,36] and (2) avoiding a heat or high-pressure compaction approach ^[19][37][19,37].