بررسي طول بهينه الياف پلي¬پروپيلن در روسازي بتن غلتكي

In recent decades, due to the increase in temperature and the effects of thermal differences and the increase in traffic with heavy axles, the use of roller concrete pavements is increasing due to its advantages. Due to the weakness of roller concrete against tensile stresses caused by loading, changes in heat and humidity, which causes cracking and reduced durability, resulting in the deterioration of the roller concrete pavement. Therefore, in order to improve the quality level of concrete by increasing tensile strength and resistance to fatigue against dynamic loads, by increasing its plasticity in order to preserve natural resources and national capitals and develop technical knowledge, researchers are always looking for materials to be used with concrete. are. Concrete (composite concrete) has been rolled in order to increase the quality level of concrete pavements. In this research, to investigate the effectiveness of using polypropylene fibers consisting of four different types of fibers and each type with different lengths (10 to 50 mm) in the construction of roller concrete in order to increase the physical properties and durability of roller concrete, based on Brazilian compressive and tensile strength tests. bending, modulus of elasticity and permeability have been discussed In this regard, although the indirect tensile test could not show the influence of the fiber parameters in the rolled samples of concrete reinforced with polypropylene fibers in relation to the tensile strength index of the samples, but by creating a difference in the failure mode of the samples. It pro‎mp‎ted us to further investigate the role of fiber parameters on net tensile strength and ductility of reinforced concrete samples by performing bending beam tests. With the right type, shape, length, diameter and amount, it plays a significant role in increasing tensile strength, compressive strength, modulus of rupture and improving adhesion properties and reducing cracking, followed by increasing ductility. Acceptability, durability and increase in fatigue resistance, in order to increase the life of roller concrete pavement, so that the first rank of 7-day compressive strength with a value of 48.3 MPa with an increase of 43% compared to the control sample to the roller concrete sample reinforced with Kurta Aqua fibers 30 mm long and 0.5% fibers. In terms of tensile strength, the first rank of the 7-day maximum tensile strength belongs to the rolled concrete sample containing 20 mm Polytar-wave fibers and 1.5% fibers with a resistance of 4.4 MPa, which shows a 2.32% increase compared to the control sample with a value of 4.3Mpa. The first rank of 7-day bending strength and fracture energy absorption belongs to the rolled concrete sample containing 40 length and 0.5 mm diameter Aqua Kortta fibers with 2% fibers, with 7-day bending strength. 7.2 Mpa and a 100% increase compared to the control sample (3.6) Mpa and with a fracture energy of 3636 and a 298% increase compared to the control sample.According to the collection of all test answers and data analysis of four types of fibers in the form of group comparison, in total, the rolled concrete sample containing polytarsinus fibers with a length of 40 mm and 3% fibers in the modulus of elasticity compared to the control sample is 8.77 The percentage has decreased. Maintaining the tensile strength of Brazil according to the control sample (4.3 MPa), with a compressive strength of 41.2 MPa with an increase of 21.5% compared to the control sample, with a flexural strength of 6.6 MPa, an increase of 83% compared to the control sample. With the fracture energy absorption value of 2264, an increase of 148% compared to the control sample and a 90% increase in permeability resistance during care under wet conditions for 28 days in order to maintain and increase all physical resistance characteristics along with increasing ductility and durability and fatigue resistance

5

35916