Experimental Research On Shear Capacity Of Inclined Section Of Polypropylene Fiber Lithium Slag Concrete Beams

Polypropylene Fiber Concrete(Polypropylene Fiber Reinforced Concrete, referred to as PFRC) is a new kind of high performance concrete, it not only keeps the excellent compressive strength of concrete material, but also makes the tensile, bending strength and fracture toughness of the concrete material improved. At the same time, the polypropylene fiber concrete has a strong acid alkali resistance, thermal conductivity, and has the extremely stable chemical properties and excellent durability.Xinjiang lithium salt plant is Asia’s largest manufacturer which produces lithium salt products with ore as raw materials. At present, the international market demands for lithium series products rising at an annual rate of 15% ~ 20%, but every tons of lithium carbonate production would discharge about ten tons of lithium slag waste. Rational use of lithium slag not only can reduce cost, but also is conducive to protect the environment.Therefore, this paper carried out the experimental study on the basic mechanical properties of polypropylene fiber lithium slag concrete; Tensile strength of concrete block is directly proportion to the shear capacity of concrete beams, so do the performance of polypropylene fiber lithium slag concrete beams oblique section shear, put forward the polypropylene fiber lithium slag concrete beam and calculation formula of the cracking load and ultimate load,which can provide the certain reference for project practices.Firstly, according to the "Specification for mix proportion design of ordinary concrete"(JGJ 55-2011), we got the C30 and C50 common concrete mixture ratio, studying that lithium slag has effect on the properties of concrete compressive. Fixing the optimum dosage of lithium slag(the highest compressive strength),on the basis of its,we can test the mechanical properties of polypropylene fiber lithium slag concrete. Found that with the increase of dosage of polypropylene fiber,compressive strength and tensile strength are increased linearly; Test of axial compressive stress- strain curve fitting curves are coincide well with known model curves.Secondly, we studied that the related factors, which are polypropylene fiber reinforcement content, stirrup reinforcement ratio, shear span ratio and concrete strength grade affect the polypropylene fiber lithium slag concrete beam inclined section shear cracking load and ultimate load. This paper will refer to the "Technical specification for fiber reinforced concrete structures"(CECS38-2004), determine the polypropylene fiber on the beam inclined section is influenced by shear cracking load coefficient and shear the influence coefficient of ultimate load, discuss the polypropylene fiber lithium slag concrete beam inclined section method for calculating the shear cracking load and ultimate load.Finally, through the test of beam load- displacement curve, using the R.Park method tests the beam displacement ductility coefficient. we studied that the related factors, which are polypropylene fiber reinforcement content, stirrup reinforcement ratio, shear span ratio and concrete strength grade affect the polypropylene fiber lithium slag concrete beam displacement ductility coefficient.