Journal of Civil Engineering Beyond Limits (CEBEL)

Joseph Ejelikwu Edeh Manasseh Joel Jonah Ogbu Edoka

The functionality of a highway pavement is often judged by the quality and engineering properties of the soil-pavement structures and the materials used to improve the properties of these underlying soils. In this study, crushed concrete waste and carbide waste, whose associated disposal problems constitute environmental hazard, were used for the stabilization of clayey soil using British Standard heavy (Modified Proctor) compaction energy, and used as highway construction material. The various mixes were subjected to particles size analyses, specific gravity, moisture content, Atterberg limits, compaction characteristics, California bearing ratio, unconfined compressive strength test triaxial and water absorption tests. The test results show that the properties of the clayey soil improved with its stabilization with crushed concrete and carbide wastes. The maximum dry density decreased from 1.93 to 1.29 Mg/m3 with corresponding increase in optimum moisture content from 6.0 to 16.6 %, as carbide waste content increased, and crushed concrete waste and clayey soil contents of the mixtures decreased. The maximum California bearing ratio value of 55.01 % (unsoaked and soaked for 24 h) recorded for 25%CS + 75%(75%CCW + 25%CW) mix can be used as subbase material in flexible pavement construction. Further work may assess resilient modulus of this material under cyclic load.

https://doi.org/10.36937/cebel.2020.003.001

Saad Issa Sarsam Samah Abdulrazzaq AL Nuaimi

The bonding strength provided by the tack coat between asphalt concrete layers at the interface is considered as an essential issue in the performance of the flexible pavement throughout its service life. However, the surface texture of the pavement surface exhibit another essential issue in the bond strength. In this investigation, three layers of asphalt concrete (base, binder and wearing) courses with (25, 19, and 12.5) mm of nominal maximum size of aggregates have been prepared using roller compactor. Rapid curing cutback RC70 and cationic medium setting emulsion CMS have been implemented as tack coat with three application rates. The slab specimens were subjected to mean texture depth determination using sand patch method. Core specimens of 102 mm diameter were obtained from the prepared slab samples and subjected to interface bond strength test with the aid of special manufactured mold. Test results were analyzed and compared. It was concluded that when RC-70 tack coat was implemented, asphalt concrete binder course laid on base course exhibit the highest shear strength of 1600 kPa at an application rate of 0.33 liter/m2 when compared to other application rates. Asphalt concrete wearing course laid on binder course exhibit the highest shear strength of 1515 kPa at an application rate of 0.15 liter/m2 when compared to other application rates. When CMS tack coat was implemented, asphalt concrete binder course laid on base course exhibit the highest shear strength of 1620 kPa at an application rate of 0.23 liter/m2 when compared to other application rates. However, the asphalt concrete wearing course laid on binder course exhibit the highest shear strength of 2272 kPa at an application rate of 0.23 liter/m2 when compared to other application rates.

https://doi.org/10.36937/cebel.2020.003.002

Zaidoon T. Abdulrazzaq

Rainfall data are considered an important and critical element of many environmental and hydrological studies such as drought, desertification, climate change and other strategic studies. These studies are mainly based on the rainfall data archive for previous years. During the last two decades, a large number of meteorological stations have been destroyed as a result of wars and internal conflicts, reducing the stations to 16 after the number was more than 30 stations, resulting in a significant lack of meteorological data archive. In addition to the spatial distribution of these stations does not adequately cover Iraq. The research aim to evaluate the feasibility of the TRMM satellite data (3B42 V7 product) to complete the rainfall data archive of the missing terrestrial stations. Several rainfall contour maps of the season 2017-2018 were drawn from data of 16 terrestrial stations, 16 and 30 stations derived from TRMM satellite data, and a hybrid map derived from the TRMM satellite data and available terrestrial stations, afterwards there were compared with the general rainfall contour map. The correlation was made between the satellite data and terrestrial stations data, and the results showed a positive correlation with a strong correlation coefficient reach to 0.91. The results showed that TRMM data could be used as a good alternative to terrestrial station data for its accuracy, wide coverage and ease of availability.

https://doi.org/10.36937/cebel.2020.003.003

Khalid Abdel Naser Abdel Rahim

This article presents a design appraisal for the construction of a water off-take channel following Construction Design and Management regulations (CDM). Furthermore, a case study to pump water from River Tay near the village of Luncarty requires the construction of a water off-take channel (abstraction channel). An initial section plan of water abstraction scheme has been conducted. The design will be reviewed by taking into consideration the main concerns regarding Health and Safety concerning Construction Design and Management Regulations (CDM) 2007 and its amendments in 2015. Mostly, the greatest attention will be given to the construction stage of the project where these concerns will be questioned in terms if they can be catered for in designing the water take-off channel.

https://doi.org/10.36937/cebel.2020.003.004

Abbas Al-Taie

The design process in geotechnical engineering has been vastly affected by Atterberg limits. There are wide variances in the results of liquid limit(LL)determined by different methods. It thought that the procedure used in the test is the primary source of these variances. The research reported in this paper was carried out to find the extent of the proper variance caused by the procedure used to determine the LL of quaternary soils. The effect of this variance on soil classification and activity (A) were included thoroughly. The LL was determined by six methods. They are the Casagrande hard-base and soft-base devices (multi-point and one-point method, and multi-point and one-point cone penetrometer methods. It was found that the index properties obtained from hard-base Casagrande device are differed significantly when compared with other methods. The variance noted was great enough to change LL and change the classification of soil from CL to CH and cause an error in computing A.

https://doi.org/10.36937/cebel.2020.003.005