No abstract

Construction materials constitute a major cost component in any construction project. The total cost of installed materials (or value of the materials) may be 50% or more of the total cost. Cost estimating is an assessment of the expected cost of any construction project. The accuracy of such an estimate has a serious effect on the expected profit of the construction contractor. Hence, a certain contingency premium should be added to the base estimate to increase the level of confidence. Such premium is materially affected by many factors. Through this research, the main factors that are expected to affect the accuracy of the construction materials' cost estimate were clearly identified. The numbers of these factors 46 were collected from the literature review. The twelve factors are identified as the most important factors. These factors were: Unsettlement of the local currency in relation to dollar value, fluctuation of price of raw materials, project materials monopoly by some suppliers, fraudulent activities of subcontractors, standard procedure for updating cost information, poor contractor experience for project type, improper planning and errors during construction, engaging in adequate skill on labor, waste control during material usage, location of project, improper construction methods and improper supervision at site and control.

A nonlinear strain compatibility model is considered to investigate the behavior of reinforced concrete deep beams. It is based on satisfying equilibrium of stresses and compatibility of strains at all layers of the beam cross-section. A VISUAL BASIC code is developed for this model. Strain distribution over the cross section depth in deep beams is different from shallow beams, and varies according to the case of loading, the span-to-depth ratio (L/h), and the structural system. The experimental values of strain over the cross-section depth for different cases for simply supported deep beams, are extracted from the available literature. Based on these values, simplified equations for strain profiles for each case is proposed to use them in the present model. A key feature of the model is the ability to illustrate the effect of shear deformation of the cross section. The model is validated by comparing predicted results with experimental ones from literature in terms of load-displacement.amounts of tension reinforcing steel are considered [3]. The stress and strain distribution along the deep beam depth are different from that in RC shallow beams.

Eccentric punching shear loads most likely take place on flat plate floors. This type of structure has been investigated experimentally and analytically by many researchers. Most of those experimental studies have dealt with slab specimens as a freeedge supported. This testing technique audits, in turn, slab specimen edges to leave the free support when exposed to an eccentric shearing load. So, slab deformed shape, in this case, does not represent that of the real floor slab when subjected to eccentric shear loading. This work investigates the behavior of the slabs under eccentric punching shear loads with the most realistic different techniques of the true slab condition and certainly gives more accurate results. Flat plates with concrete dimensions (600 x 600 x 60) mm were tested under variable eccentricities (50 -70 -100 )mm. Also, the effect of the flexure reinforcement ratio was studied. The ultimate load capacity, central deflection, cracking progress and pattern of cracks are recorded and discussed. The failure loads were compared to those calculated from different design codes. It was concluded that increasing eccentricity leads to a reduction of failure loads. Also increasing flexure reinforcement increases the failure loads. Moreover, it was observed that the expected failure loads from different design codes were lesser than the experimental results.

The main premise of transaction cost economics is that project cost is not only production costs but there are also additional costs resulting from transactions between parties. Transaction costs include _but are not limited to_ the costs of preparing the bidding package, estimating and drawing up a contract, administering the contract, dealing with any deviations from contract conditions and any contractual problems include claims, change orders, and disputes. The main objective of this paper is to establish the factors that affecting transaction costs in construction projects in Egypt. The study was conducted on various types of construction projects in Egypt, which formed the sample size. To collect data, a questionnaire was used that was personally administered to the respondents, using emails and conducting semistructured interviews. The collected data were analyzed by using SPSS program, and a software package named IBM. The findings indicated that the most important factors affecting positively (decreasing transaction cost value) on transaction cost value in construction projects in Egypt are: 1-The good financial position of the contractor 2-Lack of claims by the contractor 3-Non-substitution of materials during implementation by contractor 4-Contractor's experience in similar type projects 5-The good relationship between the contractor and previous clients 6-Choose a more qualified contractor to do the job 7-The good relationship between the owner and contractor, designers, suppliers and government agencies 8-Implementation of the project in a stable security circumstance 9-Owner's obligation to pay the contractor in time 10-The high efficiency of communication between project parties 11-Owner's commitment to his orders and not change during execution 12-The high efficiency of the owner's organization 13-Choose the appropriate procurement method 14-Calculate the project time correctly 15-Choose the appropriate delivery type