Comparative Study on Compressive Strength of Locally Produced Fired Clay Bricks and Stabilized Clay Bricks with Cement and Lime

The local fired brick production technique is the known method of brick making, especially in Jimma Town. Firing of bricks in local brick production method is conducted by burning of much amount of woods. But this method of firing bricks by burning of woods will affect the environment. The locale firing technique is difficult to control the firing temperature, which will result in non-uniform burnt bricks. The major objective of this experimental study was to compare the compressive strengths of locally fired clay bricks and the local unfired cement and lime stabilized clay bricks. Specifically, the index properties of soil used for brick production, the compressive strength of locally fired clay bricks, and stabilized clay bricks had been determined and compare with the standard specifications. This study, it was used contents of the stabilizer for cement and lime of 10%, 12%, and 14%, respectively. The mix ratio applied 1:9, 1:7, and 1:6 by volume of clay with stabilizer 10%, 12%, and 14%. Based on the result on the 28th day, the mean compressive strength test, the 10%, 12%, and 14% cement Stabilized clay bricks have compressive strengths of 2.91Mpa, 3.28Mpa, and 3.79Mpa respectively, which are better than the mean compressive strength of the locally fired clay bricks which is 2.73Mpa. On the other hand, the 28th day means compressive strengths of the lime stabilized clay bricks were 2.19Mpa, 2.51Mpa, and 2.69Mpa, respectively. Therefore, these results showed that the Fired Clay Brick fails the minimum mean compressive strength requirement based on the ES, ASTM, and IS standards. But the Stabilized Clay Bricks fulfill the minimum compressive strength requirements of IS standard for stabilized bricks. Among these three methods, the cement stabilized clay bricks indicated better quality than both locally fired and lime stabilized bricks

Evaluation of the Performance of Brick Dust as a Filler Material for Hot Asphalt Mix Design A Case Study in Jimma Zone

A bituminous paving mixture is a mixture of coarse aggregate, fine aggregate, and bitumen mixed in suitable proportion to result in a strong and durable mix in order to withstand traffic load. In this paving mix, ordinary stone dust, and cement used as filler material. One of the main problems in the construction of a bituminous paving mixture is the insufficient amount of filler from crushing stone aggregate, and cement supply is low. A study has been carried out in this research to explore the use of Brick dust as filler material for the bituminous mixture. The objective is intended to evaluate the performance of brick dust as fillers in Hot Asphalt Mix design, according to the test procedure specified by ASTM. Several specimens of hot asphalt mixture were prepared according to ASTM D 1559 using an aggregate blend with brick filler and aggregate blend without brick filler. The aggregate blending made by using Job mix formula to obtain the percentage of mixed material. For aggregate blended without brick G-1 32%, G-2 23%, and G-3 45% for Aggregate blended with brick filler G-1 30%, G-2 18%, G-3 45% and G-4 7%; where G-1 Coarse Aggregate 3/4, G-2 Coarse Aggregate 3/8, G-3 Fine Aggregate, and G-4 brick filler. It concluded that the results of the Marshall test of mix design showed satisfactory when hot asphalt mixed with these brick fillers. The Specimens blended with brick filler lead produce asphalt mixture with higher Marshall stability, lower flow, a less void filled with asphalt. Hence, brick dust can replace stone dust and cement filler in the bituminous paving mix. It is recommended to use brick dust as filler material in a bituminous paving mix may save considerable investment; as well as a reliable performance of the in-service highway can be achieved

Investigation of Pedestrian Safety Problems and Its Countermeasures: A Case Study in Nekemte City, Ethiopia

The actual growth of urban economic activities and simple movements of peoples and goods measured through its primary transport system. The requirements of the pedestrian should be considered in the design of the urban environment and transportation facilities. Since road infrastructure improvements and designed pedestrian environments are an essential part of road safety enhancements that increase walking and decrease fatalities. This study investigated the pedestrian safety problems and its countermeasures on road segments in Nekemte city. This study examined the existing issues affecting the safety of pedestrian movement, evaluates the service quality of walking facilities, and finally identified the most significant factors affecting pedestrian safety with engineering countermeasures in the city. For the data analysis, the study used both objective measurements and subjective assessments to model PLOS using Australian methods. As per field study indicates 60% of the respondents' think the sidewalk is not user-friendly. In the city, the built road infrastructure is lacking pedestrian facility management and appropriate maintenance activities. Since the walkways in Nekemte city, in general, have almost the same problems like non-continuous, crack, and non-covered utility holes which are difficult especially for pedestrians with disabilities. The current sidewalk is encroached either by vendors, utility poles, parking carts or illegal construction materials in different places, and crosswalk facilities are not visible and not enough provided at a logical distance. The Pedestrian LOS analysis indicates that poor pedestrian conditions exist and the factors that negatively affect pedestrian LOS are wide-ranging in this city road segment. It concluded that Pedestrian facilities and all the concerned factors should be provided and maintained to more efficient for both encouraging people to walk and improve pedestrian safety

EXPERIMENTAL STUDY OF STABILIZED EXPANSIVE SOIL USING PUMICE MIXED WITH LIME FOR SUBGRADE ROAD CONSTRUCTION

Unsuitable soil materials along the alignment of road projects have a significant influence on planning, design, construction, and maintenance. Expansive soils are susceptible to considerable volume changes due to seasonal variations and moisture content. Most soils found in Jimma and Ambo Zones composed of plastic clay soil, causing severe damage at the intermittent of pavement sections. This research study conducted laboratory investigation considering combinations of materials blended to stabilize the expansive soil for subgrade construction. An experimental type of study performed started by collecting specimens. Two clayey soil specimens considered to test the free swell index obtained from a depth of 1.5m to remove the organic impurities. Results indicated the chemical analysis of pumice contained 82.68%, while its physical properties of the test of fineness specific surface and residue on 45 microns showed 3770 cm2/gm and 30%, respectively. As the lime content increased, the CBR strength also increased. But, if the percent content of lime decreased with an increasing pumice content, the CBR value did not show any significant increase. Both the chemical and physical properties satisfied the requirements according to ASTM C-618. Hence, this experiment obtained 7% lime + 3% pumice as an optimum mix ratio to stabilize expansive soils

Regression Analysis of Index Properties of Soil as Strength Determinant for California Bearing Ratio (CBR)

Investigation of the variation in different soil types and origins is an essential task for Geotechnical engineers. To overcome the effects of this change, the Geotechnical engineers, as well as other professionals, attempted to develop empirical equations unique to a region and soil type to use the soil for its intended purpose. However, these empirical equations are more reliable for the kind of soil where there is a strong relationship of parameters is developed. Hence, it is good practice to develop empirical equations that best fit the soil available in the location that we can access. On the flexible pavement, the subgrade is considered to be an ideal layer to resist wheel load, and its CBR value is considered as the strength measuring a parameter. Conducting a CBR test is an expensive and time-consuming procedure. Also, it is challenging to mold the sample at a desired in-situ density in the laboratory. Furthermore, if the available soil is of poor quality, suitable additives are mixed with soil, and the resulting strength of the soil is assessed by the CBR value which is cumbersome. To overcome such a problem, statistical approaches such as regression-based models are used. This can be used for quick and easily determined parameters. Relative to this, the study has been conducted to develop an equation to show the relationship between the index properties and CBR values precisely located along WelkiteArekit –Hosanna Road of about 121km stretches. It was carried out using thirty samples retrieved from this road and tested in a laboratory. The test result of the regression-based statistical analysis was used to develop the predetermined relationship. The relationship development was performed in the form of an equation of CBR as a function of grain size parameters, Atterberg’s liquid limits, and compaction parameters by considering the effect of individual soil properties as well as the effect of a combination of soil properties on the CBR value. Based on the results of the study for both linear and multiple linear regression analyses, it was revealed that there was a relatively fair relationship obtained by combining plasticity index, the percentage of fine content, and maximum dry density which are strength determinants of fine-grained soils. Also, the results showed that the coefficient of determination for multiple linear regression is R2=0. 731, while for single linear regression is R2=0. 682. Therefore, it is concluded that the index properties of soils are sufficiently accurate in determining the CBR values, of which it can be utilized for preliminary characterization

Investigation of Traffic Accident Prone Areas Related to Existing Road Condition and Driver’s Behavior along Menagesha- Ambo Road Section

Traffic accidents worldwide are increasing due to pragmatic vehicle ownership, acquisition, which necessitates daily activities. The primary objective of this research work was to identify the most hazardous location and provide countermeasures that will minimize traffic accident at the designated sites. The scope of the study was limited to Ambo-Ginchi- Addis Ababa road, a total length of the study road section of 87kms. The traffic accident data collected from each Wededa Police station covering the period of 2012-2015. It was analyzed using a Priority value formula for EjereWereda and Holota town, and accident frequency for Ambo wereda, Dendiwereda, and Welmeraweredato rank the traffic accident areas. Based on the results of the analysis, thirteen locations of the road stretch were found to be accident-prone areas. Out of these sites, three of them are in Ambo Wereda, two in Ejerewereda, one in Welmerawereda, and seven in Holota town. The time when most of the accidents occurred from 3:00 PM-6: 00 PM. The primary causes of the accidents were overspeeding, driving without attention, and some unknown reasons. Also, it showed that the drivers’ age group who caused most of the accidents composed of 25-34 years old. Based on the findings of the study, it is concluded that there was a significant increase in the number of crashes in the afternoon. Young drivers are believed to cause more accidents than older ones due to aggressiveness. To minimize the occurrence of accidents along the study road section, it is recommended that provision of speed limit signboards and warning signs at the strategic locations where traffic accident areas are identified to forewarn the overspeeding drivers. It is also recommended that the road agency should have to undertake to widen the lane width of the road, provision of sufficient climbing lane, installation of roadside Delineator, conduct roadside improvements, and repaint faded pavement markings

Investigation of Pedestrian Safety Problems and Its Countermeasures: A Case Study in Nekemte City, Ethiopia

Volume 8 Issue 2 (February 201