Author/Authors :
Rahmani, K Department of Civil Engineering - Science and Research Branch - Islamic Azad University, Tehran , Ghaemian, M Department of Civil Engineering - Sharif University of Technology, Tehran , Hosseini, S.A Department of Civil Engineering - Science and Research Branch - Islamic Azad University, Tehran
Abstract :
This study investigates the effect of nano-silica on mechanical properties
and durability of concrete containing polypropylene fibers. Herein, the length and the
length-to-diameter ratio of used polypropylene fibers were considered fixed and equal to
18 mm and 600, respectively, and the cement content was 479 kg/m3. The effects of
fibers and nano-silica in four different percentages of 0.1, 0.2, 0.3, and 0.4% volume
for fibers and 3% for nano-silica in concrete with water to cement ratios of 0.33, 0.36,
0.4, 0.44, and 0.5% were compared and evaluated. In total, more than 425 cubic and
cylindrical specimens were made according to ASTM standards. Finally, samples of
polypropylene fiber containing nano-silica were tested under compressive loads,
flexural
strength, indirect tensile strength (Brazilian test), abrasion resistance, permeability, and
porosity; in addition, their mechanical properties were evaluated. The test results showed a
significant improvement of mechanical properties and durability of concrete. Compressive
strength, tensile strength,
flexural strength, and abrasion resistance (of concrete) increased
by 55%, 25%, 49%, and 45%, respectively. In addition, a considerable reduction in hydraulic
conductivity coeffcient by 50% indicates the high durability of these types of concrete.
Keywords :
Concrete , Nano-silica , Mechanical properties of concrete , ASTM standard
