Investigation on Cracking of Concrete Shear Wall under Exceeded Temperature Differences Rate

In situ, the changes of temperature, deformation, and stressing of steel bar of C40 reinforced concrete shear wall were measured, respectively. The results are obvious that the temperature change of climate is one of the most effective factors which could lead the concrete shear wall to cracking at earlier age. The temperature differences between inside and outside concrete shear wall are so large that the concrete will gain larger shrinkage. This larger shrinkage which is caused by the temperature reducing ratio will gain the strained action of head, end and reinforced steel bar of concrete shear wall. This action can lead to tensile stress on the surface and inside concrete shear wall. If the tensile stress would exceed the pull strength of concrete, the concrete shear wall would crack and cause deterioration. Thus, the enhancing curing of concrete shear wall in suit at earlier age, and controlling temperature reducing ratio and deform caused by shrinkage, will be available treatments which control occurring and developing of cracking on concrete shear wall.

Structural Analysis of a RC Shear Wall by Use of a Truss Model

Purpose of present work is to develop a reliable and simple method for structural analysis of RC Shear Walls. The shear wall is simulated by a truss model as the bar of a truss is the simplest finite element. An iterative method is used. Initially, there are only concrete bars. Repeated structural analyses are performed. After each structural analysis, every concrete bar exceeding tensile strength is replaced by a steel bar. For every concrete bar exceeding compressive strength, first its section area is increased. If this is not enough, a steel bar is placed at the side of it. For every steel bar exceeding tensile or compressive strength, its section area is increased. After the end of every structural analysis, if all concrete and steel bars fall within tensile and compressive strengths, the output data are written and the analysis is terminated. Otherwise, the structural analysis is repeated. As all the necessary conditions (static, elastic, linearized geometric) are satisfied and the stresses of ALL concrete and steel bars fall within the tensile and compressive strengths, the results are acceptable. Usually, the proposed method exhibits a fast convergence in 4 - 5 repeats of structural analysis of the RC Shear Wall.

Structural Retrofitting of Old Illyria Hote

Illyria hotel （formerly Bozhur） was built during the sixties in the heart of the actual Kosovo＇s capital Prishtina, according to former old Yugoslav standards in a Modernist architectural style. It represents a massive structural system with brick walls up to 54 cm thick and ＂avramenko＂ type reinforced concrete floors. The investor＇s aim was to add another two floors on the top of the existing ones and to build two level underground parking floors, a health spa centre, whilst at the vicinity of the existing building （the northern side） to erect a new 17 story-high brand new hotel and administration building. The retrofitting of the structure as well as construction of the new structure has been done in full accordance with the new structural Eurocodes＇ recommendations. 3D FEM （finite element method） modeling was used for the analysis and design, using ETABS v 9.5 nonlinear and ARSAP 2010 （Autodesk Robot Structural Analysis Professional 2010）. Response spectrum design according to EC 8,3.2.2.4 has been used for seismic analysis and design with a reference peak ground acceleration on type A ground Of AgR = 0.25 g.