Behaviour of Steel Stud Shear Connectors in Self-Compacted Lightweight Aggregate Concrete Modified with Plastic Fibres

Abstract

Composite structures having lightweight concrete have become increasingly popular in the last three decades because of increasing population and industrial development. The effect of lightweight aggregates and fibers in self-compacting mixtures in different proportions was studied. After the mixture passed the fresh and hardened tests, it was used to prepare the composite specimens using push-out tests with Section dimensions of 150 ×150 mm and shear connectors. In the current study, a shear connector stud with a diameter of 19 mm, having two lengths of 60 mm, and 90 mm, was used, as well as a shear connector stud of a diameter of 13 mm, having two lengths of 60 mm, 90 mm .It was tested under a constant monotonic load at 5 kN/s. It was concluded that, with increasing the diameter of the shear stud, the ultimate loads and slipping increased, the ultimate load capacity increased by (25.6) %, while the slipping capacity increased by (44.6) % when the shear stud diameter increased by (46)%. Also, the ultimate loads and slipping increased according to shear stud length. The ultimate load was about increase was (3.6) % and 70.2% in the slipping when the shear stud length increased by (50) %. For concrete mixes containing polyolefin fibers, it was concluded that the ultimate load capacity increases by (32.1) %, while the slipping increases by (42.1) % when the shear stud diameter increases by (46) %. Also, the ultimate loads and slipping increased according to shear stud length, this increase was (3.6) % in the ultimate load capacity and (32.3) % in the slipping when the shear stud length increased by (50) %. Uses Self-compacting lightweight aggregates concrete (SCLAC) and self-compacting lightweight aggregates concrete with fibers (SCLACF) were used. Five volume proportions (0%, 0.25%, 0.5%, 0.75%, and 1%) polyolefin plastic fiber (PPF) on Severally fresh features and behavior of self-compacting lightweight concrete mixtures. Several tests were performed to evaluate the features of SCLAC, and SCLACF fiber-reinforced polyolefin fiber concrete, When the adding successful ratio III of fibers for SCLAC is added at 0.25%. There is a decrease in (stagnation flow, Lbox, separation index) by (7.2%, 6.7%, 10%) respectively. And in the same percentage of fibers increasing the time passing the mixture for (T500, V-funnel) by (21.7%,114%) respectively .and decreasing (dry density, water absorption, porosity, penetration, thermal conductivity, and Ultrasonic pulse velocity) by (0.4 %,3.1%,2.7%,15%,3.7%,and 2%) respectively. Also, increasing the (compressive strength, modulus of elasticity, splitting, and flexural strength ) by (3%,10.8%,17.3%, and 1.3%) respectively. Finally, increasing the (compressive strength, modulus of elasticity, and flexural strength ) for the self-curing specimens by (5.5%,4.2%, and 11.2%), respectively.