الفهرس Only 14 pages are availabe for public view
 |  | from | 152 |  |  |
| | | from | 152 | | |
Abstract
Glass Fiber Reinforcement Plastics (GFRP)-bars are non-corrosive materials This advantage made them suitable to be used as reinforcements for concrete elements exposed to aggressive environments such as top roof slabs, liquid tanks, harbor docks, etc from previous works it was found that the concrete elements reinforced with GFRP-bars have larger deflection, wider cracks than the ordinary reinforced concrete elements this Is because of different parameters such as the lower elastic modulus of GFRP-bars if compared with steel and the lower bond strength between the concrete material and the smooth surface of the GFRP-bars. To overcome these weak points result from using GFRP-bars instead of steel as reinforcement, the concrete mixture and the smooth surface of GFRP-bars must be improved This may be done by addIng the polypropylene fibers to the concrete mixture and roughening the smooth surface of GFRP-bars by wrapping them by helical fiber yarns. Experimental study has been conducted on numbers of one-way slabs specimens to Investigate such improvements. Twenty- three slabs were tested The first group was reinforced with high tensile steel bars of slabs reinforced with steel as base control specimens. The other slabs were divided Into eight groups. This grouping procedure was based on three parameters namely the GFRP-bars diameters (10, and 12mm), bars surface (smooth and wrapped by helical fiber yarn of pitches of 1, 3cm) and the amount of the polypropylene fibers added to the concrete mixture (0, 15 and 2 kg/m³) The flexural behavior of the slabs was evaluated by studying the crack patterns, modes of failure, the load-mid span deflection relationship, the deflected shape and the reinforcement strains Comprehensive between specimens reinforced with GFRP-bars and the steel specimens are made in order to reach for valuable both recommendations and conclusions to help in providing some guidelines for design purpose.