Experimental Investigation of High-Strength Concrete Using Urmia Local Materials

This research seeks to introduce high-strength concrete ‎(HSC) ‎using Urmia local materials (ULMs) in the aspects generally expected from this type of concrete volume unit. HSC is a type of concrete whose 28-day characteristic unconfined compressive strength ‎(UCS) is more than 40 MPa. The strength of normal-strength concrete (NSC) is between 21 and 40 MPa. Experimental investigation shows that in many cases, the properties and microstructure of concrete with a UCS of more than 40 MPa are different from NSC. For this purpose, a total of 28 samples were made in 4 mixing designs with different ‎cement ratios‎‏ and 0.35 water-to-cement ratio (W/C) and fixed aggregate consumption for ‎UCS tests were ‎conducted ‎on 50 mm cubic samples at 7, 14, ‎and 28 days of curing. Before the test date, samples were prepared under standardized ‎conditions ‎‎and cured in a tank with limewater saturated at 23±1C°.‎ Under the standard, the average of two samples calculated the UCS value for each ‎‎day test. The ‎results show that HSC can be made by using ULMs. The highest UCS was related to the 28-day strength of the UL-04 mixing design with ‎the highest amount of cement used (600 kg/m3), around 65 Mpa. The findings of the present research ‎show that the UCS of concrete increases with the increase in curing time ‎and the amount of cement used under standard conditions, under the W/C ‎and aggregate fixed.‎ In this research, the investigation possibility of producing HSC using ULMs shows favorable mechanical properties and at the same time provides a sustainable alternative for making HSC, which brings economic benefits and reduces environmental disadvantages such as CO2 global emissions caused by the transportation of materials.