Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Load


Mechanical Properties of Reactive Powder Concrete (RPC) with Various Steel Fiber and Silica Fume Contents

Lubna S. Danha; Wasan Ismail Khalil; Hisham M. Al-Hassani

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3090-3108

An experimental work was carried out to investigate some mechanical properties
of Reactive Powder Concrete (RPC) which are particularly required as input data for
structural design. These properties include compressive strength, tensile strength
(direct, splitting and flexural), flexural toughness, load-deflection capacity and static
modulus of elasticity. The effects of three variable parameters on these properties were
carefully studied which are, the silica fume content SF (0%, 10%, 15%, 20%, 25%, and
30%) as a partial replacement by weight of cement, hooked macro steel fibers volume
fraction Vf (0%, 1%, 2% and 3%) and superplasticizertype(Sikament®-163N and
PC200).The diameter of the steel fiber is 0.5mm and its length is 30mm with aspect
ratio 60.The experimental results showed that as the silica fume content (SF) increases
from 0% to 30% the compressive strength significantly increases, while the increase in
tensile strength is relatively lower. The inclusion of steel fibers leads to a considerable
increase intensile strength, while the addition of steel fibers causes a slight increase in
compressive strength of RPC as fiber volume fraction increases from 0% to 3%.The
increase in the steel fibers volume fraction and silica fume content improved the loaddeflection
behavior and consequently gave higher ductility and fracture toughness of
RPC.

Numerical Analysis of Piled Raft Foundation on Clayey Soil

Hussein H. Karim; Mahmoud R. AL-Qaissy; Mudhafar K. Hameedi

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1297-1312

The piled raft foundations allow an increase in the load capacity and reduction of settlements in a very economic way as compared with the traditional foundation concepts. Due to the development of structures that use piled rafts as a foundation system, an extensive numerical modeling study was performed considering different factors and conditions. This study highlights the percentage ratio of bearing loads between the pile and the pile cap (raft). Present modeling results obtained by computer program (Plaxis 3D Foundation V 1.1) have been verified with an experimental work of the same problem using the same configuration but extended to include 8 and 16 piles with raft for different soil layers. In addition, a comparison of the present results is achieved with another a theoretical study using the program (Ansys). The finite element method through Plaxis program evaluates the effect of parameter on the load-settlement behavior of the piled raft foundation. The effect of spacing between piles on the load-settlement behavior of the piled raft foundation was also studied. The percentage of the load carried by piles to the total applied load of the numerical model for case sixteen piles with raft is around 42%. The contribution to carry the load of piles relative to the total load is decrease with the increase of the spacing to diameter ratio. The percentage of the load carrying for piled raft for the case of two piles with raft only decreases about 23% when the spacing between piles increases from 3 to 10 times pile diameters.