Semnan University International Journal of Nonlinear Analysis and Applications 2008-6822 2026 05 17 Study on the mechanical properties and behavior of reactive powder concrete under various conditions and curing 10637 10.22075/ijnaa.2026.40128.5605 EN Mohammad Jalil Jihad Karakosh Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran Mojtaba Fathi Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran Journal Article 2025 12 21 In this Study, the mechanical and behavioral characteristics of reactive powder concrete under different percentages of microsilica, quartz, and steel fibers under different temperature and pressure curing conditions were studied. In this research, the amount of microsilica was 10, 15, 20%, quartz powder was 10, 15, 20%, steel fibers were 1, 1.75, 2.5%, and for curing conditions, three temperatures of 25, 50, and 75 degrees Celsius for water were considered. Also, all experimental specimens were tested once in conditions without pre-pressure and a second time in conditions with a pre-pressure of 10 MPa. In these specimens Stress-strain diagram, compressive strength, tensile strength, ductility, energy absorption, cracking pattern, and SEM electron image of the experimental specimens were investigated. The results of this Study showed that increasing quartz powder, microsilica, steel fibers, water temperature and pre-pressure increased compressive and tensile strength by about 10, 15, 20 and 30 percent, respectively. Increased energy absorption by about 10, 35, 50, and 85 percent, respectively, and the combination of the above factors improved the mechanical properties of concrete by about 100 to 140 percent. Fracture images and SEM showed an increase in cracking and more adhesion and ductile fracture with extensive fine cracks in the specimens. https://ijnaa.semnan.ac.ir/article_10637_67caec8041b2d689a5035d3bf441c34c.pdf