The distress of moisture induced damage in flexible pavement received tremendous attention over the past decades. The harmful effects of this distress expand the deterioration of other known distresses such as rutting and fatigue cracking. This paper focused on the efficiency of using the waste material of demolished concrete to prepare asphalt mixtures that can withstand the effect of moisture in the pavement. For this purpose, different percentages of waste demolished concrete (0, 10, 20, 30, 50, 70 and 100) were embedded as a replacement for coarse aggregate to construct the base course. The optimum asphalt contents were determined depending on the Marshall method. Then after, two parameters were founded to evaluate the moisture susceptibility, namely: the tensile strength ratio (TSR) and the index of retained strength (IRS). To achieve this, the indirect tensile strength test and the compressive test were performed on different fabricated specimens. The results show that mixtures with a higher percentage of demolished concrete possess higher optimum asphalt content as this parameter increased from 3.9 % for control mixture to 4.5 % for mixture with coarse aggregate that fully replaced by demolished concrete. This work indicated that optimum percent of waste demolished concrete that can be utilized in the asphalt mixtures is 30 %, whereas this percent recorded higher value of increased increments for TSR and IRS by 10.6 % and 7.9 % respectively.
Pultruded materials made of Fiber-Reinforced Polymer (FRP) come in a broad range of shapes, such as bars, I-sections, C-sections, etc. FRP materials are starting to compete with steel as structural materials owing to their great resistance, low self-weight, and cheap maintenance costs, especially in corrosive conditions. This study aims to evaluate the effectiveness of a novel concrete Composite Column (CC) using Encased I-Section (EIS) as a reinforcement in contrast to traditional steel bars by using Glass Fiber-Reinforced Polymer (GFRP) as I-section (CC-EIS) to evaluate the effectiveness of the hybrid columns which have been built by combining GFRP profiles with concrete columns. To achieve the aims of this study, nine circular co
... Show MoreThis research investigates the pre- and post-cracking resistance of steel fiber-reinforced concrete specimens with Glass Fiber Reinforced Polymer (GFRP) bars subjected to flexural loading. The purpose is to modify the ductility and cracking resistance of GFRP-reinforced beams, which are prone to early cracking and excessive deflections instigated by the low modulus of elasticity of GFRP. Six self-compacting concrete specimens (1500×240×200 mm), incorporating steel fibers of two lengths (25 mm and 40 mm) with varying distribution depths, were tested to assess their structural performance. The results indicate significant enhancements in cracking resistance, stiffness, energy absorption, ductility, and flexural strength. Tested beam
... Show MoreThe main objective of this study is to examine the impact of moisture concrete of clayey soil on the concrete slabs placed directly over it. This experimental study presents the mechanical properties of the concrete slab when placed on different clayey soil moisture content ranging from 0% to the optimum moisture content of 35%. The tests were performed on soil concrete specimens of 25*30*50 mm exposed to sprayed water curing conditions for 28 days. Tests of compressive strength, ultrasonic pulse velocity, crack depth and crack width were investigated through this paper. An ejection relationship between compressive strength of concrete and water content in the soil was observed, with a 26% increase with water increasing from 0% to 35%. T
... Show MoreFiber Reinforced Polymer (FRP) bars are anisotropic in nature and have high tensile strength in the fiber direction. The use of High-Strength Concrete (HSC) allows for better use of the high-strength properties of FRP bars. The mechanical properties of FRP bars can yield to large crack widths and deflections. As a result, the design of concrete elements reinforced with FRP materials is often governed by the Serviceability Limit States (SLS). This study investigates the short-term serviceability behavior of FRP RC I-beams. Eight RC I-beams reinforced with carbon-FRP (CFRP) and four steel RC I-beams, for comparison purposes, were tested under two-point loading.
Deformations on the concrete and crack widths and spacing are measured and
There is an interesting potential for the use of GFRP-pultruded profiles in hybrid GFRP-concrete structural elements, either for new constructions or for the rehabilitation of existing structures. This paper provides experimental and numerical investigations on the flexural performance of reinforced concrete (RC) specimens composite with encased pultruded GFRP I-sections. Five simply supported composite beams were tested in this experimental program to investigate the static flexural behavior of encased GFRP beams with high-strength concrete. Besides, the effect of using shear studs to improve the composite interaction between the GFRP beam and concrete as well as the effect of web stiffeners of GFRP were explored. Encasing the GFRP
... Show MoreSocial factors may affect the available sources of toxic substances and causes of poisoning, and these factors may change over time. Additionally, understanding the characteristics of poisoning cases is important for treating such patients. Therefore, the present study investigated the characteristics of poisoning cases in Baghdad Poisoning Consultation Center (PCC) and Forensic Medicine Institute (FMI). Data on all poisoning cases reported in PCC and FMI during 2013 were retrospectively obtained from medical records. Total of 1131 reports of poisoning cases (1082 from PCC and 49 from FMI) were analyzed according to age, sex, geographical distribution and causes of poisoning according to the type and class of poisoning agent. The results
... Show MoreThe kaizen is considered as one of the most important modern techniques which has been adopted by various economics entities especially manufacturing firms and its beginnings return to the middle of the earlier century that has been used by companies like Toshiba, Matsushita Electric, and Toyota. Which realized that these modern techniques would make a total change in the competitive environment and started qualifying and its staff in such away that enables them to go along with this unique environment. The continuous improvement (Kaizen) depends on the small continuous improvements in the product and the production operations during the production stage. Consequently, the research problem is represented in the improperly of the budg
... Show MoreForm of investment in infrastructure important factor to drive economic growth in any country, with the dwindling ability of governments to provide the necessary funds for such investments, emerged as a rising trend for private sector involvement in public projects and infrastructure, and one of these trends is the build-operate-transfer system (BOT), which commonly used in various developed and developing countries as one of the tools used in the implementation of these investments, as the private sector under this system design, finance, build and operate the project, and are re-administration of the state after a certain period under a contractual agreement between the parties of the contract. As this system provides majo
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