Title: Factors Affecting Cost Overrun in Road Construction Projects in Saudi Arabia

Abstract:The aim of this study is to identify the factors causing cost overrun in road construction projects in Saudi Arabia from contractors’ viewpoint. The risk map of 41 factors considered in a survey indicates that the most factors affecting cost overrun in road construction projects are: internal administrative problems, payments delay, poor communication between construction parties, and delays in decision making.

Title: Ductility of RC Beams using Grade 72.5 Re-bar Steel

Abstract:Production of high strength (Grade 72.5) re-bars has recently started in Pakistan. Use of these re-bars in structural members (such as beams) was studied through use of a computerized model based on strain compatibility realistic stress-strain curves of concrete and reinforcing steel to assess the strength and ductility aspects. It can be concluded that RC beams with Grade 72.5 have adequate strength but have lesser ductility than RC beams reinforced with Grade 60 steel.

Title: Investigation of Fracture in Reinforced Concrete Masonry Walls

Abstract:The study of fracture of materials under compression is a comparatively new field. So there are quite more to discover in this sphere. The basic concept of fracture of materials under compression such as concrete, masonry, rock etc. has been developed though there are many disputes regarding various topics yet. In masonry it is still unknown what should be the relation between the compressive strength of the material and the tensile stress that causes the first cracking. This paper made an attempt to find out this relation by examining various test results of reinforced concrete masonry walls. The tensile strength while the first cracking is determined assuming two types of flaws in the masonry: spheroidal and cylindrical. Study is also made to find the types of flaws that might actually exist in masonry. It was found that the ratio of compressive to tensile strength of masonry might range from 3-10 as obtained from the results reported herein. Again spheroidal assumption seem to give close result to the actual tensile strength.

Title: Experimental Investigation on Nanomaterial Concrete

Abstract:Nanomaterial concrete is new generation concrete formed of materials of the grain size of nanoscale. The composition of nanomaterial concrete consists of cement, nanosilica grain of the size of 10 nm - 140 nm, fine sand of the grain size of 0.125 mm - 0.50 mm, quartz powder of the size of 16 ?m - 90 ?m, coarse aggregate of a maximum grain size of 15 mm, and superplastisizer. Nanomaterials have properties or functions different from similar materials of large size. Nanomaterials have a larger value of the ratio between surface area and volume than other similar particles in larger size, making the nanomaterials more reactive. This paper presents the influence of nanosilica as a partial substitution of cement in concrete. The presence of nanosilica in concrete is intended to accommodate the byproduct of the cement hydration production in the form of free hydroxide calcium. Nanosilica will react with C3S and C2S in the cement and produce CSH-2 that will form a strong and solid bond of gel. The results showed that the addition of nanosilica as cement partial substitute material could improve the mechanical behavior of the concrete.

Title: Factor Analysis of Meteorological and Granulometrical Data of Aeolian Sands in Arid Area as a Geo-Environmental Clue: a Case Study From Western Bank of Lake Nasser, Egypt

Abstract:A monitoring program of sand accumulation process over an arid area of about 28000 km2 is carried out at the western side of Lake Nasser along a distance of ~ 350 km between Aswan city and Egyptian-sudanese borders. From geoenvironmental point of view, calculations of the flow rate of wind blown sands from the Western Desert of Egypt and evaluation of their encroachment hazards into Lake Nasser are of ultimate importance. In conjurent with the local metereological data, the granulometriacal data is evaluated. It showed that the overall graphic mean (Mz) of these aeolian sands ranges from 1.18 f to 2.48 f medium to fine grained sand. Sorting ranges from 0.6 to 1.8 f moderately well to poorly sorted. Meteorologically, the mean air pressure varies between 940 and 1001 mbar, whereas the mean air temperature varies between 16.0 and 40.5 °C. The mean humidity is low and ranges between 15.6% and 48.8%. The mean wind speed in the study area ranges between 3.0 and 7.1 m/s. The prevailing wind direction is from north or north-northwest. The interrelationships between the grain size parameters and the climatic-regime in the present study dry desert have been statistically modeled using factor analysis procedure. Data are studied by factor analyses including 19 original variables are proportional to their contribution to the factor loads, in order to learn the relative importance of each principal variable in determining the variations among the samples. Seven factors comprising temperature, mud, wind speed, pressure, gravel, humidity and mean size are recognized. These are represent the paramount controlling factors governing the flow rate and style of blown sands in such ideal arid region.

Title: Study of Estimation Model for Maximum Flow Discharge with Rational Model (Case Study of Bantimurung Catchment Area in Maros Regency of South Sulawesi)

Abstract:Hydrology modelling has developed and this useful for water resources management basic data. This study intends to estimate the maximum flow discharge with using Rational Model. This study is the experimental study done in laboratory to get data as a model parameter. The rational model parameter is run off coefficient, soil type, slope, land cover, rain intensity, and Catchment Area. The result of this study indicates that applied rational model in the Bantimurung Catchment Area to predicate maximum flow discharge become under estimate amount of 6. 85 % if to be compared with result of the field measurement. However, this difference falls within acceptable range (5 to 10%). It can be concluded that, the discharge rate gathered from this experimental model is accurate and therefore is an acceptable method for the estimation of maximum discharge rate.

Title: Experimental Study of Estimation Model for Direct Run-off Volume with Soil Conservation Service (SCS) Model (Case Study of Bantimurung Catchment Area in Maros Regency of South Sulawesi)

Abstract:Hydrology modelling has developed and this useful for water resources management basic data. This study intends to predicate direct runoff. Method which is used is one that has been developed by U.S. Soil Conservation Service, now (Natural Resources Conservation Service, NRCS). The SCS method calculates physical condition of Catchment Area as an input in hydrology analysis. Parameter used in this method is land cover and soil type, then the physical condition to be translated into index reflecting direct run off potential called curve number. The result of this study indicates that applied Soil Conservation Service (SCS) model in the Bantimurung Catchment area to predicate the volume of direct run-off become over estimate with amount of 22.92 % in predicting maximum discharge.

Title: Classification of Engineering Consultancy Firms Using Self-Organizing Maps: A Scientific Approach

Abstract:The present study analyzed consultants in Saudi Arabia. Engineering consultancy firms work on projects worth billions of US dollars annually in the fields of design and supervision. The quality of the services provided in this field has a major impact on the national economy through various aspects of these services, such as the lifetime of the projects, their environmental effects, their efficiency, the esthetics of cities, and the societal impacts of the projects. Thus, the author investigated the knowledge, experience, human resources and financial situations of these firms, and the scientific qualifications of their professional staff. A survey was conducted using several consultancy firms and a database was constructed, while some of these firms were prequalified. The results of this exercise were revised and checked thoroughly, then used to construct a questionnaire to evaluate the firms. This study focused on applying a scientific approach to the classification of engineering consultancy firms using self-organizing maps (SOMs). An electronic version of the questionnaire was made available for all firms to complete to build the required database. A template was created using Microsoft Word to summarize the information collected, which included the prequalification data for firms and the levels of projects they handled. The summaries were converted into Excel format and used to feed an artificial neural network program. Using this program, the required information was extracted with a type of Kohonen network known as an SOM. The results were presented as tables and figures.

Title: Compression Performance of Walls of Interlocking Bricks made of Iron Ore By-Products and Cement

Abstract:This study deals with technical evaluation of the performance of walls constructed with interlocking bricks of iron ore by-products and cement under simple compressive loading. Three walls with dimensions of 150 cm width, 240 cm height and 15 cm thickness were built and tested. Testing was carried out according to the specifications of Brazilian standards. The first fissures arose with a stress of 0.56 MPa, corresponding to only 3.8% of the rupture stress of the brick alone. Horizontal displacement was negligible in all the walls and buckling was not observed. Rupture of the walls was through crushing; microfissures appeared first and evolved into fissures and then transformation into cracks. After generalized occurrence of cracks, rupture occurred. This behavior was similar to that of the bricks. Compressive load tests were also performed to determine the strength of the brick, of the prism (two overlaid bricks) and of the mortar. Results showed high compressive strength of 14.57 MPa for bricks, 9.82 MPa of the prisms and 25.2 MPa of the mortar. The walls showed good mechanical strength of 2.05 MPa, which represents 14% of the brick strength. Deformations were high, with axial deformation modulus of 420 MPa, which indicates a flexible behavior of the wall. Although the wall is flexible, the fissuration stress is relatively high, indicating excellent performance of the wall. Another very positive aspect is that this stress is only 13.6 % of the compressive strength of the wall and 1.9% of the brick, which indicates that there is a very large strength reserve.