Effect of Soorh Metakaolin on Concrete Compressive Strength and Durability

Concrete durability is a key aspect for forecasting the expected life time of concrete structures. In this paper, the effect of compressive strength and durability of concrete containing metakaolin developed from a local natural material (Soorh of Thatta Distict of Sindh, Pakistan) is investigated. Soorh is calcined by an electric furnace at 8000C for 2 hours to produce metakaolin. One mix of ordinary concrete and five mixes of metakaolin concrete were prepared, where cement is replaced by developed metakaolin from 5% to 25% by weight, with 5% increment step. The concrete durability was tested for water penetration, carbonation depth and corrosion resistance. The obtained outcomes demonstrated that, 15% replacement level of local developed metakaolin presents considerable improvements in concrete properties. Moreover, a considerable linear relationship was established between compressive strength and concrete durability indicators like water penetration, carbonation depth and corrosion resistance

Effects of Climate Change on Mountain Waters: A Case Study of European Alps

The Alps play a vital role in the water supply of the region through the rivers Danube, Rhine, Po and Rhone while they are crucial to the ecosystem. Over the past two centuries, we witnessed the temperature to increase by +2 degrees, which is approximately three times higher than the global average. Under this study, the Alps are analyzed using regional climatic models for possible projections in order to understand the climatic changes impact on the water cycle, particularly on runoff. The scenario is based on assumptions of future greenhouse gases emissions. The regional model results show the consistent warming trend in the last 30-year span: temperature in winter may increase by 3 to 4.5°C and summers by 4 to 5.5°C. The precipitation regime may also be altered: increasing about 10-50% in winter and decreasing about 30-60% in summer. The changes in the amount of precipitation are not uninformed. Differences are observed particularly between the North West and South East part of the Alps. Due to the projected changes in alpine rainfall and temperature patterns, the seasonality of alpine flow regime will also be altered: massive rise will occur in winter and a significant reduction in summer. The typical low flow period during winter will also be shifted to late summer and autumn

3D Numerical Modeling of Pile Group Responses to Excavation-Induced Stress Release in Silty Clay

Development of underground transportation systems consists of tunnels, basement construction excavations and cut and cover tunnels which may encounter existing pile groups during their construction. Since many previous studies mainly focus on the effects of excavations on single piles, settlement and load transfer mechanism of a pile group subjected to excavation-induced stress release are not well investigated and understood. To address these two issues, three-dimensional coupled-consolidation numerical analysis is conducted by using a hypoplastic model which takes small-strain stiffness into account. A non-linear pile group settlement was induced. This may be attributed to reduction of shaft resistance due to excavation induced stress release, the pile had to settle substantially to further mobilise end-bearing. Compared to the Sp of the pile group, induced settlement of the single pile is larger with similar settlement characteristics. Due to the additional settlement of the pile group, factor of safety for the pile group can be regarded as decreasing from 3.0 to 1.4, based on a displacement-based failure load criterion. Owing to non-uniform stress release, pile group tilted towards the excavation with value of 0.14%. Due to excavation-induced stress release and dragload, head load of rear piles was reduced and transferred to rear piles. This load transfer can increase the axial force in front piles by 94%

Quality Analysis of Urea Plant Wastewater and its Impact on Surface Water Bodies

This study was conducted on the canal water that flows besides an urea manufacturing facility. The study focused to evaluate the impact of facility’s effluents. The canal water quality is being affected drastically due to heavy load of pollutants discharged. Samples were collected by grab sampling method, from various locations. These samples were analyzed regarding physiochemical parameters, i.e. temperature, pH, TDS, TSS, BOD5, COD, heavy metals (Fe, Cu, Cr, Mn) and NH3 content. The canal water quality deteriorates after receiving a substantial load of effluents discharged from urea fertilizer plant. The results compared with WHO and NEQS, showed that the effluent samples had alkaline nature with a high level of ammonia and BOD5 and are not safe for aquatic life and environment. It is therefore recommended that discharge of untreated effluents should be stopped, or allowed within safe limits

Groundwater Quality Analysis for Human Consumption: A Case Study of Sukkur City, Pakistan

Drinking water quantity and quality is of the utmost importance. If the drinking water gets contaminated, it can result in severe health problems. For example, the continuous consumption of drinking water containing more than permissible amounts of fluoride can lead to bone deterioration and increased risk of bone fracture [1]. The present study was carried out to check the quality of underground water of Sukkur city. The analyzed parameters were fluoride, sodium, magnesium, calcium, potassium, iron, arsenic, TDS, pH, conductivity, odor, color and taste. World Health Organization (WHO) standards were followed in present study. Underground water samples were collected from 20 different populated locations of Sukkur city. Only arsenic, pH, iron and potassium were found to be within health safe limits while the rest of the parameters exceeded the permissible standards set out by WHO. The TDS, sodium, fluoride and magnesium were over the limits at some locations