Journal of Engineering and Sustainable Development (JEASD)

Shear behavior of (9) modified reactive powder lightweight concrete beams (MRPLWC) beams without web reinforcement under a two-point loading system, are studied. A number of variables are used to show their effects on the diagonal cracking load and ultimate shear load. Those variables are volume fraction of fiber (Vf), the ratio of longitudinal reinforcement (ρ), and the ratio of the shear span to the effective depth (a/d). The test results show that the shear strength increased by increasing the volume fraction and the ratio of longitudinal reinforcement, while a reduction in shear capacity is noticed by increasing the ratio of shear span to effective depth (a/d).

The main objective of this paper is to study the shear capacity of SCC reinforced concrete deep beams subjected to axial load. Seven simply supported deep beams cast by using SCC mix with steel fibers and tested. All these beams have dimensions of 1300mm length, 350mm high, and 150mm width and have been subjected to constant axial force with value (100) kN and then subjected to two-point loads. The variables of this work are (shear span/depth (a/d), vertical shear reinforcement (ρv), and horizontal shear reinforcement (ρh) to study their effects on first crack and ultimate loads, and mid-span deflection.

In Iraq, the infrastructures are developing rapidly, so it is necessary to consider the hydrology of the developed catchment before constructing any drainage facilities such as culverts to prevent traffic disruption during rain. In this study, sizing of box culvert for highways in Iraq is proposed using the rational method for determination of peak runoff from small catchment (less than 3 km2). However, soil conservation service curve number (SCS-CN) was used in the estimation of peak runoff from a catchment with sizes ranging from 3 to less than 30 km2. HY-8 computer software was used for sizing square and circular sections. The appropriate sizes for square sections in large basins are 3 m to 4 m and 2 m to 2.9 m for more than 114 m3/s and 32 m3/s, but for circular sections, diameters were 4.1m, from 3 m to 3.8 m and from 2.5 m to 2.9 m under flow rates more than 160 m3/s, 68 m3/s and 25 m3/s in sequence. However, for small basins, square sections sizes were 3m to 3.1m and 2 m to 2.7 m for flow rates more than 23 m3/s and 8 m3/s in sequence. Diameters for circular sections were 3 m to 3.2 m and 2 m to 2.9 m under flow rates 23 m3/ s and 8 m3/s in sequence.

This study aims to evaluate the resistance of Lime-Pozzolana concrete mixtures to external sulfate attack, represented by studying their effect on compressive strength, splitting tensile strength, dynamic modulus of elasticity, and weight loss. Three types of pozzolanic materials are used in concrete mixtures; Silica fume (as LS mix), Silica fume-Fly ash (LSF), and Metakaolin (LMK). LS and LSF mixture was exposed to 5% concentration of MgSO4 solution, while LMK mix was exposed to 5% concentration of NaSO4 solution until 210 days after moist curing in tap water until 14 days age. Results indicate that specimens of mixtures (LS and LSF) didn’t disintegrate when subjected to the very harsh environment of MgSO4 solution until 210 days of age. There was no visual sign of deterioration nor a significant loss in specimens weight of the two mixes at the end period of exposure of 210 days age. While LMK mix specimens disintegrate at 180 days of age due to exposure to Na2SO4 solution.

Due to the increasing demand for communications services, particularly the application of broadband multimedia services, it has become necessary to search for easy, low cost, and reliable communications with information security. Communications via power lines PLC have become an attractive environment for communications services because of the power grid covering large areas of the world. This research will discuss the most important factors affecting the efficiency of PLC systems and will focus more on the distance between modems and change in load within the network. A set of modems has been connected to the local area network LAN, performing the tests at different distances, then switching the load and observing changes in system efficiency. The practical results have shown that the long-distance had a negative effect, also the change in load has a significant negative impact on the rate of transfer of information and efficiency, as described later in the practical section. Therefore requires further practical research and full knowledge of other challenges that currently limit their widespread commercially PLC application.

Due to the increased demand for more sustainable building environments, and the excessive need in the building field to meet the designer’s requirements such as irregular,complex-shaped structures, the utilization of three-dimensional technology (3D printing or additive manufacturing (AM)) by engineers in the construction sector is increased globally. The key advantages of using the 3D printing method over traditional building methods are low labor cost, fewer waste materials, freedom in design, faster construction, no need for formwork, and reduced risk and safety issues in construction sites. In theory, the printing is based on using 3D computer-aided design (CAD) to materialize the whole building structure by just pressing a button in the 3D printer that brought to the construction site while the reality is not like that. This paper presents the most recent developed innovative methodology used for 3D printing, possible printed building materials and the existed 3D printed structures in reality towards spotting the light on the most high-tech applications in construction and the possibility to adopt such technology in Iraq to overcome the challenges in design with faster building methods towards developing the country in the construction sector.

As sustainable construction intends to optimize the use of natural resources and because of the importance of water resources, the self -curing could be assigned as a sustainable strategy. This study introduces self-curing cement sand mortar with specific properties concern compressive strength, consistency by using sodium polyacrylate as an additive. The sodium polyacrylate has a wide range of uses for any purpose, for its ability to absorb water and it's good mechanical, physical, and chemical properties. This study assesses the possibility of using it with traditional raw materials for developing self-curing high workability cement sand mortar which could be useful in many construction applications such as ferrocement slabs and building partitions. The study assigned the possibility of using sodium polyacrylate in gel fashion within cement sand mix as efficient additives for self-curing, as well as its positive effect upon compressive strength and consistency of cement sand mortar comparing with specimens cured with the traditional technique of immersing them within water for a week. Specimens of sodium polyacrylate to cement ratio (S/C) between 1 to 5 % as a gel (with constant water-cement ratio, W/C=50%) developed significant strength improvement in absence of any curing techniques, compressive strength upgrading ratio assigned between 1.12 to 1.25 with respect to specimens cured by water for seven days while excellent ratio (1.37) associated with the positive effect of specific W/C ratio beside sodium polycraylate effect.

The use of powders with attractive wear and friction has increased attention in industrial sectors and research. In this study, the experimental work results of the tribological behavior of base oil SN500 with CuO and ZrO2 as anti-wear and anti-friction hybrid additives powders at concentrations (0.5, 1, 2, and 4) wt. % was obtained and comparing the results were with pure oil. Therefore the effect of normal loads and sliding speed under mixed lubrication were studied according to ASTM G-99 pin on disc and ASTM G-77 block on ring principles for friction and wear measurements respectively. The optimum lubrication concluded on the level of concentration of the hybrid powder was at (2) wt. % by the formation of the protected boundary layer in the significantly improved i.e. friction coefficient decreased about (20.8%) and the wear rate about (46%) as compared with the case of using pure lubricant oil.

Due to the increasing cost of asphalt binder, significant economic savings can be realized by using the amount from reclaimed asphalt pavement (RAP) in the production of new hot mix asphalt (HMA). Moreover, this is an environmentally friendly option as it reduces the demand for virgin materials. It has to be remarked that in Iraq RAP is not used in the production of HMA and this valuable material is mostly degraded for use in lower value applications. Four mixtures were designed, which contains three different percent RAP, it is (0%, 5%, 15%) with asphalt grade (40-50) and (25%) with asphalt grade (60-70), it has been changed the grade of asphalt when adding RAP (25%) to compensate for the aged binder in the RAP when adding to mixture. All types of test result demonstrated that all mixtures have good properties compared with the virgin mixture. This demonstrated that mixtures with RAP content could be successfully designed to meet the local volumetric and performance-specification requirements.

Warm mix asphalt (WMA) is mixed at temperatures ranging 20 – 50 °C lower than those in which is called hot mix asphalt (HMA). The use of synthetic zeolites as a warm mix asphalt additive has exhibited many additional advantages, such as reduced susceptibility to permanent deformation. However, there are also indications that the use of synthetic zeolites as a warm mix asphalt additive for some percentages increases the moisture sensitivity of pavements except for 5% there is a slight improvement. The results of the study indicated that the selected percentages of synthetic zeolite to the warm asphalt differently affected the mixture properties. When the mixture properties were compared, it was observed that WMA with 3% of synthetic zeolite reduced the indirect tensile strength value, also the WMA mixture with 5 % of synthetic zeolite decreased the rut depth of the mixtures and slightly increased in the tensile strength ratio (TSR).

Numerical and experimental investigation of the heat transfer and the friction factor characteristics in a counter flow double pipe heat exchanger with and without Nano fluid was studied. Tests are performed for fully developed turbulent flow ranges, homogeneous Nano fluid. The double pipe heat exchanger consists of two tubes, the first inner plain tube has been manufactured from copper materials with inner and outer diameters of (11.2 and 12.7) mm respectively, the length of the first inner plain tube is 1057 mm. The second insulated an external tube which has been manufactured from PVC material with inner and outer diameters of (44.4 and 50)mm respectively, with a length is 1032mm. The flows have been tested at Reynolds number ranging (3019.43-4824.22). Nano particle size ranging (15-20)nm. The results show that the heat transfer rate increases as Reynolds number and volume concentration of Nano fluid increase. The increasing percentage of Nusselt number, friction factor and the performance factor of (15.72,11.51 and 11.57) % respectively for maximum volume concentration and volume flow rate of 3% and 1.6 lpm respectively. ANSYS FLUENT 2015 package was used to simulate the heat transfer and the fluid flow in the heat exchanger. The results show that the heat transfer increases when Nano fluid was added. The agreement was observed with experimental work with a maximum discrepancy of 12%.

This study includes a series of bond tests related to reinforced concrete beams with rectangular cross-section (140x150) & span of 600 mm that are provided with shear reinforcement. The specimens are tested as simply supported beams with one point load with strain reading in steel bar by strain indicator placed in a hole (recess) prepared for this purpose. The displacement between the steel bar and the concrete at the free end of the bar has been measured. Three groups of beams have been tested to study the effect of many variables on bond strength for Self Compacting Concrete (SCC ) and conventional reinforced concrete (CC). The variables are: [steel bar diameter (8, 12 and 16) mm, concrete compressive strength (30, 60) MPa and type of curing (tap water continuous curing, saline water wetting and drying, saline water continuous exposing) for a time of (90 days). The study also involves the effect of each variable on bond strength and comparison between the results of all the specimens of SCC and CC bond stress-slip relationships. The results of comparison between all specimens of SCC and CC bond stress-slip relationships show that the CC bond strength is lower than the SCC bond strength in two cases of curing (tap water continuous, saline water continuous exposing), but in the case of saline water wetting and drying, the CC bond strength is higher than SCC bond strength.

The objective of this study is to improve the properties of structural foamed concretes by adding fine and coarse lightweight aggregate. The materials that used in this study were fly ash as fine material and various types of lightweight aggregate (Leca, porcelanite). The mechanical properties included fresh and hardened density, compressive strength and elasticity modulus were tested in this study. The results show increases in compressive strength and modulus of elasticity by increasing the percentage of fine aggregate (fly ash). The optimum percent is 50% for fine aggregate (fly ash). The compressive strength decreases with increasing the percentage of lightweight coarse aggregate. The modules of elasticity increase by increasing the replacement percentage of fly ash. The addition of lightweight coarse and fine aggregate effect on the percentage of foam needs to be added to the mix for the desired density. Type of aggregate has a significant effect on compressive strength and modulus of elasticity for foamed concrete. Flyash increased compressive strength by about (39%). Lightweight aggregate decrease in compressive strength about (2-50) %. Flyash increase in modulus of elasticity about (10-56)% and lightweight aggregate increase in modulus of elasticity about (1-20)%. Fly ash and lightweight aggregate (Leca and Porcelanite) improved the properties of foamed concrete.

This study investigates the possibility of using waste heat from the car engine cooling system to drive an absorption refrigeration system by using four different refrigerant solutions (water - lithium bromide/ammonia - water/ammonia - sodium thiocyanate/acetone - Zinc bromide). Four mathematical models had been built (model for each solution) to simulate the performance of the system and to compare the performance of different solutions. Engineering Equations Solution (EES) program had been used to perform this simulation. The results were as follows: Using refrigerant solution (water - lithium bromide) at the conditions of no load on the engine can produce (14kW) cooling capacity at evaporator temperature (14C°). While for the conditions of loaded engine it produced (32kW) cooling capacity at evaporator temperature (17C°). Using refrigerant solution (ammonia - water) at the conditions of no load on the engine can produce (12kW) cooling capacity at evaporator temperature (15C°). While for the conditions of loaded engine it produced (27kW) cooling capacity at evaporator temperature (17C°). Using refrigerant solution (ammonia- sodium thiocyanate) at the conditions of no load on the engine can produce (11kW) cooling capacity at evaporator temperature (15C°). While for the conditions of loaded engine it produced (23kW) cooling capacity at evaporator temperature (17C°). Using refrigerant solution (acetone - zinc bromide) at the conditions of no load on the engine can produce (13kW) cooling capacity at evaporator temperature (16C°). While for the conditions of loaded engine it produced (32kW) cooling capacity at evaporator temperature (17C°).

This research includes a Functionally Graded Polymeric Composite )FGPCs). These Composites were fabricated from unsaturated polyester resin as a matrix reinforced with silicon carbide particles) SiCp) of different particle size ) 53,106,150 µm) and )6 vol%) bulk volume fraction produced by Gravity Casting and room temperature )22°C) and produced sample from pure polyester to use it in
comparison. The aim of the present research is to study the effect of the change in )SiCp) particle size on the local value of volume fraction, hardness, and Youg modulus at specific points along with the graded samples, and graded samples were cut to nine portions with thickness )8mm) and density, bulk volume fractions were calculated, then and tensile test. Results show that local values of volume fraction, hardness and Young modulus decreased in pure end samples and increased in lower end samples because increased particles SiCp in this position.

The purpose of this research is to know the change that happened in the current land uses of the city of Samarra in relation to the proposed master plan of the year 2010, in which all land uses were zoned according to the legislations and laws of the Ministry of Municipalities and Local Government. In order to identify the excesses that happened in the various land uses, determine its type, area, and proportions relative to the other uses. Furthermore, identify the reason for the excesses in land use, and the possibility of controlling this miss-use, by providing alternatives to these land uses, or change their functions, or treating the defect in these uses. This study has succeeded in identifying the types of land uses that do not correspond to the master plan, its proportions, its areas, and the reasons for the changes that have occurred in these uses, it also identifies the shortfall in these land uses, in order to develop a future strategy to re-develop the master plan or remedy the imbalance, through modern planning methods. The study was based on the GIS system in analyzing the location of the study area and in obtaining the required results in a short period of time and less cost and effort as possible.