Civil Engineering Dimension (E-Journal)
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The Comparison of Engineering Properties Between Single and Double Layer Porous Asphalt made of Packing Gradation
Get PDFis paper presents the comparison of engineering properties between single and double layer porous asphalt (SLPA and DLPA) made of packing gradation. Three nominal maximum aggregate sizes (NMAS) were tested each made up of 10, 14, and 20 mm for SLPA. While for the DLPA with 30, 20, and 15 mm top layer are made of 10 and 14 mm NMAS, with a base layer of 20 mm NMAS. Total thickness of all mixes is 70 mm. Binders used are 60/70 penetration base bitumen and polymer binder styrene-butadiene-styrene (SBS). The result shows that the properties of SLPA mix namely permeability and resistance to abrasion loss decreases when the NMAS in SLPA decreases. The abrasion loss of DLPA mixes increases when the porous asphalt top layer thickness decreases, while drainage time value decreases. However, SLPA with 20 mm NMAS exhibits higher abrasion loss compared to all DLPA mixes
Adaptive Meshless Local Petrov-Galerkin Method with Variable Domain of Influence in 2D Elastostatic Problems
Get PDFA meshless local Petrov-Galerkin (MLPG) method that employs polygonal sub-domains constructed from several triangular patches rather than the typically used circular sub-domains is presented. Moving least-squares approximation is used to construct the trial displacements and linear, Lagrange interpolation functions are used to construct the test functions. An adaptive technique to improve the accuracy of approximate solutions is developed to minimize the computational cost. Variable domain of influence (VDOI) and effective stress gradient indicator (EK) for local error assessment are the focus of this study. Several numerical examples are presented to verify the efficiency and accuracy of the proposed adaptive MLPG method. The results show that the proposed adaptive technique performs as expected that is refining the problem domain in area with high stress concentration in which higher accuracy is commonly required
One-Dimensional Hydrodynamic Modelling for River Flood Forecasting
Get PDFThe ability to forecast maximum water depth during maximum discharge of a design flood is very important in designing flood protection scheme along the river reach. This paper explains the use of ISIS Flow, a one-dimensional hydrodinamic computer modelling for river flood forecasting. The computer simulations produced detailed information from each node including the maximum water depth during maximum discharge, thus it can be expected that an economical flood protection structure can be produced
Chloride Penetration into Fiber Reinforced Concrete under Static and Cyclic Compressive Loading
Get PDFThe effect of loading on the chloride penetration into plain concrete (PC) and fiber reinforced concrete (FRC) was studied experimentally by using modified NT Build 492 – Non-steady state chloride migration test that include the application of loading on the specimen during the test. Three types of polypropylene fibers with different lengths and shapes were used. The concretes were tested for chloride penetration at different stress ratios under static and cyclic loading. The results of the static loading showed that there was a slight reduction in the chloride penetration under low level of compressive stress while an increase in the chloride penetration was found at higher stress level. There are significance difference in chloride penetration behavior of the plain concrete, long fiber FRC and short fiber FRC. Chloride penetration increased even more at cyclic loading conditions showing difference behavior of FRC and PC at difference number of cycle and load level
Variability Analysis of Prime Cost Sums
Get PDFThis paper investigated the variability levels of prime cost sums in building projects in order to establish the reliability of such estimates in bills of quantities. It involved a purposive sampling of forty-six executed projects in South-western Nigeria from which data on estimated and final prime cost sums as well as estimated and final contract sums were procured. Ratios interrelating the four variables were generated and their mean values determined. The mean prime cost sum overrun was found to be 41% of the estimated sums. However, a negative relationship between the prime cost sums and the final contract sums was established. Based on observed variations, models were developed to predict any of the ratios in general, and specifically, the practical prime cost range in order to effectively control overall project costs
Modeling The Influence of Project Manager Trustworthy Leadership Behavior Upon Construction Team Trust
Get PDFAppropriate trust and leadership have been frequently cited as key answer to the problems of cooperation and coordination in contractor’s teamwork. The objectives of this paper are to measure trust level of construction projects team, to investigate trustworthy leadership behavior of project managers, and to model the influence of project managers’ trustworthy leadership behavior upon team trust level. Sixty-one respondents from nine on-going construction projects participated in the questionnaire survey. The analyses show that in general the levels of trust and project managers’ trustworthy leadership behavior are medium (scores of 82.71 and 102.09 respectively). Meanwhile the positive influence of project managers’ trustworthy leadership behavior upon team trust level, modeled through multiple regression analysis with one dependent variable (i.e. trust) and three independent variables (i.e. leadership-results, leadership-integrity, and leadership-concern), is found to be significant. The model is evaluated and validated; the results reveal that the prediction of the model is satisfactory
Construction Workers Perceptions Toward Safety Culture
Get PDFEfforts to reduce construction accidents can be initiated by building good safety culture. Researches concerning safety culture, however, are still limited. This research aims to empirically gauge worker’s perception toward safety culture in construction projects. Data were obtained through questionnaire survey to three large construction projects in Surabaya. Two hundreds and seven sets of questionnaires were gathered and used for subsequent analyses. Results show that in general workers’ perception toward safety culture are quite good. Further analysis indicates that workers in the three projects have different safety culture perceptions, especially on factors of top management commitment, safety rules and procedures, communication, and worker’s competency
The Decline of Soil Infiltration Capacity Due To High Elevation Groundwater
Get PDFInfiltration capacity of soil mainly depends on two factors; the particle size and the moisture content of the soil. Groundwater increases the soil moisture, not only below the water table but also within the capillary zone, above the water table. Field experiment in a high groundwater area was conducted to understand the relationship among the groundwater, soil moisture and infiltration capacity. Using a single ring infiltrometer, the effect of groundwater in the infiltration rate was observed. This field experiment result shows that the groundwater influences significantly the infiltration capacity of the soil, and the infiltration rate follows a specific trendline
The Responses of Road Users on Safety Riding Campaign in Surabaya
Get PDFThe implementation of safety riding in Surabaya in 2006 featuring some actions including canalization (kanalisasi), daytime headlamp rule, safety belt rule and the standardized helmet are viewed by some as not suitable with the existing condition. Canalization causes unfairness among road users. The canalization lane, mandatory for vehicle such as motorcycle and public transit (bus and mikrolet) tends to suffer bigger degree of saturation compared to the others. Not to mention the indication of overuse of battery and shorter bulbs life time due to the daytime headlamp rule application. Although the evaluation of the safety riding campaign covers several aspects, this paper only discuss the responses of road users to safety riding campaign especially canalization and daytime headlamp rule. The data collecting process is carried out by distributing 332 questionnaires to all road users including motorcyclists, car drivers and public transit users. The instant responses are also collected and summarized from several websites. Furthermore, the descriptive and inference statistical analysis are deployed to give the common view of response of road users as well as tabulate the summary of website-posted response. The results show that, generally most of road users support the safety riding campaign. On the contrary, most of road users agree that the daytime headlamp rule did consume more both battery and bulbs. Meanwhile, the website-posted responses varies between agree and disagree with their own reasons
Spline Nonparametric Regression Analysis of Stress-Strain Curve of Confined Concrete
Get PDFDue to enormous uncertainties in confinement models associated with the maximum compressive strength and ductility of concrete confined by rectilinear ties, the implementation of spline nonparametric regression analysis is proposed herein as an alternative approach. The statistical evaluation is carried out based on 128 large-scale column specimens of either normal-or high-strength concrete tested under uniaxial compression. The main advantage of this kind of analysis is that it can be applied when the trend of relation between predictor and response variables are not obvious. The error in the analysis can, therefore, be minimized so that it does not depend on the assumption of a particular shape of the curve. This provides higher flexibility in the application. The results of the statistical analysis indicates that the stress-strain curves of confined concrete obtained from the spline nonparametric regression analysis proves to be in good agreement with the experimental curves available in literature