Geotechnical Perspective of the Causes of Cracks in Building of University Campus (Sindh University Jamshoro Sindh Pakistan)

The Building construction throughout world faces the defects from normal to heay and destructive like cracks and fractures which cause damages and finally collaps to heavy life losses along with economical and financial. The crack like strictures are found in wall and columns also. For the purpose of study the international experts have classified the minimum allowable standards of these defects which may not be harmful to buildings and people living there. This research study has been carried out to investigate the main reasons to investigate the causes of cracks in a newly completed and used buildings in where some distinct cracks appeared immediately and after some years. Oftenly these cracks seem in almost in walls and other structural elements such as columns and beams, with different patterns. The general methods consisting of reconnaissance survey; building inspection and laboratory testing were used to investigate the causes of these detrimental cracks. By the use of reconnaissance survey, factors that may lead to formation of cracks were considered and analyzed. The width, pattern and conditions of the cracks were identified during the building inspection stage and the soil properties related to the creation of cracks were determined during the laboratory test. Based on the outcome of the study; there is no evidence of factors such as a matured system that may lead to the creation of cracks in the building; all the cracks are active cracks with their width increasing with time and the soils in the entire block of the building possessed high percentage of fine materials with high moisture content and plasticity indices. The pore water pressure in this type of soil takes longer time to vanish, which can be expressed by very low value of the coefficient of permeability (1.90x 10-7 to 2.15 x 10-7 m/s) acquired from different soil samples collected from the study area. Hence the cracks in this type of building were found to be caused by the settlement of the building due to the nature of the predominant soil type that was found in the study area.

MODELING TENSILE STRENGTH OF CONCRETE ON PARTIAL REPLACEMENT OF CEMENT AND SAND WITH QUARRY DUST GROUND GRANULATED BLAST FURNACE AND SLAG SILICA FUMES

Tensile strength of concrete were examined on its partial replacement of cement and sand using ground granulated blast furnace and quarry dust, the study examines its behaviour at different dimensions, this is to monitor the variation effect of these parameters on the growth rates of tensile to the optimum curing age, these includes non linear conditions of tensile state, non-elastic and its brittle behaviour at all times as it express zero conditions in tension, this means that it has the ability to with stand pull force, it also reflect its weak ability to handle shear stress thus tends to cause deformation in material as it has poor elasticity. The reflection of its brittle influence the rate of tensile behaviour from concrete ductility, these are known to be a material on modern mechanics of concrete. These also considered as quasi brittle material, this behaviour were reflected as the system considered evaluating the growth rate of tensile strength that replaced cement and sand with these locally sourced addictives. the developed model monitor other reflected influential parameters such as variation of concrete porosity due it compaction in placements, tensile behaviour reflects these effect that subject it to mechanical properties of concrete, the study expressed the reaction of these parameters in the simulation, the evaluation of these affected the details variation of tensile growth rate at different water cement ratios and curing age, the tensile behaviour that were monitored are based on these factors in the study, these derived model were validated with Jaharatul et al 2018, and both parameters developed best fits correlation, the study is imperative because the system expressed the behaviour of tensile strength from concrete at different dimensions, experts can applied these concept to monitor tensile behaviour considering these parameters in its growth rates.

MODELING AND SIMULATION OF WOOD AND FLY ASH BEHAVIOUR AS PARTIAL REPLACEMENT FOR CEMENT ON FLEXURAL STRENGTH OF SELF COMPACTING CONCRETE

Flexural strength was monitor and predicted on the application improving concrete strength with wood and fly as partial replacement for cement. The study observed the pressure from the constituent of these locally sourced material that has been observed from the study to influence the flexural strength through the effect from this locally sourced addictives, the study monitors concrete porosity on heterogeneity as it reflect on the flexural strength of self compacting concrete, other condition considered was the compaction and placement of concrete, these effects were monitored at constant water cement ratio from design mix, the behaviour from this effects on the concrete observed the rate of flexural growth under the influences of these stated conditions, the simulation expressed the reactions of these effects through these parameters monitored to influence the system, numerical simulations were also applied to the optimum curing age of twenty eight days, while analytical simulation was also applied, this concept are the conventional seven days interval that concrete curing were observed, these are improvement done on the study carried out by SachinPrabhu et al 2018, these locally sourced material were experimentally applied, the simulation predictive values is at the interval of seven days of curing, which was also simulated. the predictive values were compared with the experimental values of SachinPrabhu et al 2018, and both values developed best fits correlations, the study is imperative because the system considered the parameters used on experimental and observed other influential variables that were not examined, these were not observed in the experimental procedure, experts in concrete engineering will definitely find these concept a better option in monitoring flexural strength of self compacting concrete in general.

Assessment of the Cause and Effect of Early Damage of Cobble Stone Road Construction and Its Remedial Measurements: A Case of Nekemte Town Cheleleki Sub City

Road constructing in Ethiopia is increasingly in demand to meet its medium and long term development programs. Most internal road of Oromia cities/town are cobblestone and gravel. Some portions along the alignment proposed and existing roads traversed low resistance of the subgrade that affect the stability of upper layers of cobblestones. Structural failures are observed on cobblestones roads, would it be constructed by good quality or low quality of materials. Nekemte Cobblestones Projects have been started in 2014 widely which were failed in most area today as we observed that needs to be addressed and a corresponding remedial measures must be drawn. A possible remedial measures had been organized for every observed failure or destroyed to obtain normal road condition of the study area. An assessment was made by using observation, interviews, laboratory and field test to determine the adequacy of the cobblestones, underlain material to serve as a subgrade for road construction based on project specifications and Ethiopian Road Authority (ERA) low volume road Specification. From the field tests and laboratory tests carried out, it is observed that the causes of cobblestone road failures of this road section are mainly due to the construction steps/sequence, quality of materials, road construction time, lack of proper design and quality control, absences of drainage structures, lack of highly compaction, lack of accurately fill fine aggregate and suddenly high loads vehicle applied on cobblestone road.

Study on the Suitability of Soils in Ilu Aba Bora Zone for Hydraform Block Production for Low Cost Construction

Due to a high construction material cost in Ethiopia, it is difficult to afford a shelter by most our peoples. The Hydra form block (HFB) has been identified as low-cost building material with its potential and possibility to reverse the housing problem. Laboratory tests were conducted on Mettu, Nopa, Gore, and Hurumu areas soil. Using hydra form machine with average mold size of 29*14*10cm, hydra form blocks were casted with the three percentages increment of cement. Compressive strength and water absorption tests were conducted at 28 days. The investigation has revealed that all the soil sample except Gore soil have significant characteristics that make it suitable for stabilization with recommended soil properties. From the experimental study, all the blocks except blocks produced with Gore soil have 28th day compressive strength values well above most of the recommended minimum values. Water absorption was less than the maximum limit of 15%. But, for control block and for stabilized with 3% cement, water absorption result is out of the recommended values (0-15) %. The cost comparison of Hydra form blocks with hollow concrete block and fired clay brick shows that the Hydra form block is cheapest walling material in terms of production cost and a typical hydra form block production center can create a job for more than 50 peoples.

Suitable Site Selection for Urban Solid Waste Disposal and Location Allocation Of Waste Collection Bin By Using Geographic Information Systems, In Case Of Nekemte Town

The problem of environmental pollution and health hazards due to inappropriate solid waste disposal is critical in developing countries like Ethiopia, Nekemte town is one of the town in Ethiopia facing from environmental pollution due to lack of appropriate dumping site which leads pollution of surface and ground water and environment in and around dumping area. Therefore, the main objective of this study is selection of suitable site for disposal of solid waste using Geographic Information System (GIS) tools. Selection of the most suitable landfill site was determined through the integration of geographic information system (GIS) tools, multi criteria decision analysis and remote sensing techniques. To select suitable landfill site several parameters were considered such as slope, built up area, , road, surface water, land use/land cover, geology and soil. After analysis of suitability of solid waste disposal site using GIS tools and weighted analysis methods selected 36 areas for medium solid waste Bins. Suitability map was prepared by overlay analyses on GIS based Weighted Linear Combination analysis to select the suitable solid waste disposal sites and assigned as the value given 1; unsuitable, 2; less suitable, 3; moderately suitable ; 4; Suitable and 4; highly suitable were determined. Using this method selected 2 highly suitable areas for land fill and inclination area

Analysis on the structural type of large-span steel truss bridge specially designed for cables

When the installation of cables and pipelines needs to go across rivers, bridges are usually adopted to support the cables and pipelines for crossing the rivers. The measure can make full use of the space resources and have no effect on the flow pattern of rivers. For this reason, analysis on the structural-type design of a large-span steel truss bridge specially used for cables has been performed. The numerical results indicate that the stayed-cable bridge with steel truss beam and concrete main tower has better performance and improved structural type caparisoned with that of the beam and arch bridges, and the construction of the major beam can be without the temporary support.

A Study of Fabrication Technique, Structural and Morphological Behavior of Polypropylene Reinforced with Short Natural Fiber Banana

With regard to the environmental aspect it would be very interesting if natural fibers like banana, jute, and coir could be used instead of artificial fibers and synthetic products as reinforcement in some applications. Banana .Natural fibers have many advantages compared to other man made fibers. The natural fiber composites may be used in everyday applications such as lampshades, suitcases, paperweight, helmets, shower and bath units. Polypropylene composites were fabricated with untreated and alkali treated jute fiber with 10-25% loading of fiber by weight and were designated at Polypropylene Banana Composite (PPBC). The composites of biodegradable Polypropylene (PP) reinforced with short jute natural fiber was prepared by melt mixing followed by hot press molding. The micro structural analysis and morphologies of the composites were studied via infrared spectroscopy (IR) and Scanning electron microscopy (SEM) techniques respectively. The extensive application of infrared spectroscopy is mainly due to the concept of group vibration. Any structural change like substitution or addition of groups or atoms in a molecule affects the relative mode of vibration of the group. This causes change in IR spectral band position, change in relative intensities and appearance of new bands and disappearance of any band and splitting of a single band into two or more bands. Infrared spectroscopy can also be used to increase the utility of fiber. It deals with the interaction of infrared light with matter. The former can indicate the presence of functional groups qualitatively and the latter can provide a semi quantitative measure of their concentrations. Electron Microscopy is most widely used to obtain information regarding the morphology of fiber surfaces, especially SEM (Scanning Electron Microscopy). Using SEM, it is easy to determine the differences of fiber surface topography after and before treatment, and hence the formation of fiber polymer composites. Fiber deboning was also observed for untreated and treated fiber pp matrix composite. It reveals that bonding between the fiber and the matrix at the interface may be improved. These indicate that there are some kinds of interfacial contact between fiber and pp matrix due to fiber treatment. The SEM can have a magnification range from a few times to several hundred thousand times.

Assessing the Ageing Impact on Fatigue Life of Asphalt Concrete

The fatigue life of asphalt concrete is often related to environmental condition, loading condition, ageing, material composition and properties. This work investigates the influence of short and long term ageing of laboratory beam specimens, asphalt content, and testing temperature on fatigue life of asphalt concrete wearing course. Slab samples of (30 x 40x 6) cm have been prepared, beam specimens of (40x 5x 6) cm were cut from the asphalt concrete slab samples. Beam specimens were tested for fatigue life under the influence of three levels of micro strain (250, 400, and [3]750) at (5, 20, and 30) °C before and after practicing long-term aging. It was observed that the fatigue life decreases by (85 and 97) %, (87.5 and 97.4) %, (71.4 and 95.2) % after increasing the applied microstrain from (250 to 400 and 750) μƐ for control mixture and for mixtures subjected to short-and long-term ageing processes respectively. The fatigue life increases by (142.8 and 257.1) %, (34.4 and 57.8) % and (10 and 30) % when the asphalt content increases from (4.4 to 4.9 and 5.4) % for specimens practicing the applied microstrain of (250, 400 and 750) μƐ respectively. It was concluded that the fatigue life increases by a range of (two to fifteen) folds when the testing temperature increases from (5 to 20 and 30)°C respectively.

Efficient Methodology For Design Of Industrial Electrical Substations and Control Buildings

This paper describes economical strategy for design of industrial electrical substations and control buildings. Limited literature addressed design aspects for this class of buildings. Furthermore, little guidelines are available in practice to regulate this type of steel construction. The first part of the paper overviews the architectural and structural layouts of various industrial buildings. The economical aspects and cost savings resulting in using mobile buildings are discussed. The paper also highlights the engineering challenges that are encountered in the design of mobile facilities. The transportation procedure and design requirements are briefly described. Recommendations are provided to compute the combined center of mass of the building and interior equipments. Effective analysis procedure is also described. The proposed design concept for mobile industrial buildings is cost effective and can be implemented in industry to reduce projects cost.