Study On The New-type Seam Mechanical Properties Of Precast Fabricated RC Slab

With high quality and good economic benefit and less environmental pollution, precast fabricated structure is an important part of building industrialization and modernization. In developed country, there is a higher proportion of precast concrete structure used, which is an inevitable trend for the future development of our country. Now, most scholars study on precast laminated type assembling structure, only a few scholars to study on precast non-laminated type assembling structure. In order to enrich the research achievements of precast non-laminated type assembling structure, we make the measure of the combination of static experiments and theoretical calculation and numerical analysis to investigate the new-type seam mechanical properties of precast fabricated RC slab. The main research work is as follows:Based on the previous research, this paper has a study on three kinds of new-type seam wet connection form of precast non-laminated type RC slab. The three kinds of new-type seam structural form are respectively called seam structure 1,seam structure 2 and seam structure 3. The three kinds of new-type seam structural form are considered three parameters, which include the quantity of splicing rebar, strength grade of caulking fine stone concrete and the structure form of rebar splicing. A total of 12 precast fabricated RC slabs are designed.6 specimens of them are used to study the flexural performance while the other 6 specimens are for the study on the shear performance.Through the static loading test, we preliminary discussed the mechanical properties of new-type seam structural form, and we analyzed the deflection of the specimens, cracks, steel and concrete strain.12 piece of specimen was carried out by using ANSYS numerical analysis, finally on the basis of experimental data analysis, according to the new-type seam structural damage phenomenon and the stress distribution in the form of the flexural and shear bearing capacity calculation are derived.The study showed that:The flexural ultimate bearing capacity and ductility of the flexural specimens affects significantly on the quantity of splicing rebar and the structure form of rebar splicing, while the cracking load has a little effects. The shear ultimate bearing capacity and ductility and cracking load of the shear speciments has a certain impact on strength grade of caulking fine stone concrete and the structure form of rebar splicing. Among them, the transfer performance of seam structure 1 is the the best while the ductility of it is the worst then it is prone to brittle failure. Thus, increasing quantity of reinforcement can improve appropriately brittle failure and it is suitable for the needs of large bearing capacity in seam connection; the transfer performance and ductility of seam structure 3 is poor, so it is applicable to the lower requirements in seam connection; However, seam structure 2 not only has a better transfer performance, but also has a better ductility, so it is applicable to the higher ductility and bearing capacity in seam connection. Experiment value of each new-type seam structural form, the theoretical value and the finite element analysis value are in good agreement.