الملخص الإنجليزي
Moving towards high heat insulated wall solutions may lead to more conservation of
energy both environmentally and economically. This research is focusing on
investigating the development of full-scale sandwich wall panels with high thermal
insulation properties. The use of this type of wall will enhance the preservation of
electrical energy, reduce the building cost, and reduce the construction time compared
to normal masonry walls. A total of twelve specimens have been constructed. The
panels were constructed with the full-scale dimensions which were 2.2m 0.5m
200mm (height width thickness). Three different parameters have been used in this
research study. This includes type of concrete (normal concrete and lightweight
concrete), shear ties spacing (20cm and 40cm), and using of internal reinforcement
(panels with glass fiber reinforced (GFRP) bars and panels without reinforcement). The
panels were tested in the laboratory under axial compression, out of plane bending and
in plane bending. Furthermore, a total of fifty-four cubes, eighteen cylinders and
eighteen prisms were casted to investigate concrete mixes properties such workability,
compressive strength, tensile strength, flexural strength, and thermal conductivity.
All the lightweight concrete panels showed good ultimate capacities. Although all the
specimens had lower capacities than that of normal concrete, but their capacities are
acceptable especially if they used as non-load bearing walls. The reduction in the axial
compression capacity was about 54.1% at most, that of out plane bending was 32.3%,
and the in plane bending capacity reduction was about 52.9%. In addition, the thermal
conductivity of the normal concrete sandwich wall panels ranged from 0.519 to 0.585
W/m.K whereas it ranged between 0.435-0.450 W/m.K in the lightweight concrete
sandwich panels. Furthermore, it was found that reducing the shear ties spacing from
40cm to 20cm enhanced the capacity of sandwich wall panel cast with normal concrete
by 27.2% when subjected to axial compression load. However, reducing the shear ties
spacing from 40 to 20 cm resulted in a lower failure load by 18.4% in the lightweight
concrete sandwich wall panels which could be due to the improper distribution of EPS
through the panel caused by excessive vibration. In addition, using of longitudinal
GFRP reinforcement resulted in an increase in the out of plane bending capacity of
sandwich wall panels by 91.2 % and 124.6% and an increase in the in-plane bending
capacity of sandwich wall panels by 24.5 % and 224.6% compared to the unreinforced
panels.
