Visnyk LNAU: Architecture and Farm Building 2016 №17: 107-115
TEST EXPANDED CLAY SLABS WITH EFFECTIVE ACCENTS
Voznyuk L., graduate student
Demchyna B., doctor of technical sciences, professor
National University «Lviv Polytechnic»
Sobchak-Pyastka Yu., candidate of technical sciences, associate professor
University of Technology and Life Sciences in Bydgoszcz
Considering that in the construction industry there is a constant optimization of resources and energy saving, an extremely important issue in construction to date is to reduce the weight of building structures.
Use in the ceilings of light concrete with effective inserts can significantly reduce their own weight structures, which will save resources, materials and energy efficiency of the building as a whole. Due to such constructive solutions, the load on the main structural bearing elements of the building is reduced.
Reducing the weight of floor slabs when renovating existing buildings and structures can reduce the cost of strengthening the foundations, reducing the time of execution of works.
The idea of such solutions is to replace the void-forming inserts of massive concrete in the middle of the monolithic overlappings and to reduce its own weight due to the use of claydite. In this case, the effective reinforcement of the structure is important, taking into account the peculiarities of the operation of the multilayer element.
It was tested two series of claydite floor slabs on the bend, with their support for four corners.
The experimental samples of the plates were taken square in plan, 2000×2000 mm in size, 100 mm in thickness. Plates of the first series are made of solid concrete of expanded clay. The plates of the second series were multilayered. The middle layer consisted of four inserts made of polystyrene foam (PPS) of the brand PSB-C-35 in the thickness of 40 mm, the size of the plan is 850×850 mm, the upper and lower layers of claydite thickness of 30 mm. On the perimeter of the plate and in the middle were made ribs width of 100 mm, which contained reinforcement frames.
Testing of slabs was carried out in the laboratory of ZBV № 2 plant in Lviv. The loads were loaded using fixed, pre-weighed, concrete loads. The deflection of the slabs, the deformation of the concrete and the fittings were measured using clock indicators. During the experiments, the control of the moment of cracking and the development of cracks was carried out.
The accepted technique of bending tests with short-term load allowed to determine the values of destructive loads, deformation of concrete and stretched plate fittings, deflection of structures and measure the width of crack opening.
The destruction of the first series of slabs occurred as a result of the destruction of claydite on supporting plots. The destruction of plates of the second series was due to the achievement of critical stresses in the stretched armature.
concrete elements fracture, slabs of effective inserts
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