EXPERIMENTAL STUDY OF LOCAL BEHAVIOR OF STRENGTHENED REINFORCED CONCRETE SHORT CORBEL BY BONDING CARBON FIBER FABRICS

Most of the structures in civil Engineering, after 50 years old, meet the current safety standards or have excessive cracks. Steel corrosion may also cause the occurrence of high deflection or instability of the structure itself. It is generally manifested by poor performance under service loading in the form of excessive deflections or cracking. The introduction about 34 years ago of composite materials in the field of Civil Engineering allows other strengthening orrepair of reinforced concrete structures by bonding composite carbon fiber fabrics (Abdul Wahab, 1989; ACI, 2000; Chris, 2007). Carbon fiber materials have many advantages (Ivanova, 2013): their weight, flexibility, implementation easier and also their physicochemical properties (corrosion) interesting. This technical of strengthening compensate the loss of rigidity and resistance to cracking due to the strengthening and improving performance and durability of structures.Corbel is one important element of structureto support the pre-cast structural system such as pre-cast beam and pre-stressed beam (Anis, 2012 and Rejane, 2005). The corbel is cast monolithic with the column element or wall element. It is interesting to study the local mechanical behavior of this very short element of the structure using carbon fiber materials (Mohammed, 2005; Futtuhi, 1987; Gampione, 2005; Erfan, 2010). This paper is mainly interested in the study of three types of reinforcement: by bonded carbon fiber fabrics, wrapping of carbon fabrics and by bonding plate in shear area, under flexural bending. Local deformation using strain gauges to measure strains in the steel, concrete and carbon fiber sheets of strengthened reinforced concrete short-corbel, is also investigated. In this investigation, deformations, cracking modes and collapse mechanism are studied

Quantitative study on the changes of Karst groundwater level and hydrochemistry in Jinci spring catchment, Shanxi, China

Since Jinci spring ceased to flow on April 30, 1994, it has never been reflowed, which seriously affects the sustainable utilization of karst groundwater. The purpose of this paper is to provide the basis for the reflow of Jinci spring and the sustainable protection for karst groundwater. Based on the long-term monitoring data from 1994 to 2014, this paper accurately quantifies the changes in the quantity and hydrochemistry of karst groundwater resources. By means of the Mann–Kendall trend test method, this paper analyzes the variation trends of karst groundwater level, EC, and SO42− in Jinci spring catchment. Monitoring data show that the groundwater level in the karst aquifer declined by 2.32 m from 1994 to 2008, which is equivalent to a loss of 3.3 Mm3 in aquifer storage, while the groundwater level rose by 17.67 m from 2009 to 2014, which constitutes a gain of 25.2 Mm3. The results indicate that (1) karst groundwater level showed a rising trend, which was mainly controlled by the rainfall, exploitation of karst groundwater, and the Fenhe River leakage; (2) groundwater salinity varied greatly and showed an increasing trend: increasing order of 47.83% for the six major ions, 37.52% for EC, and 3.34% for pH; (3) the increase of groundwater salinity is governed by the increase in rainfall salinity, the increase in groundwater runoff time, the recharge of the Fenhe River to groundwater, the increase of sewage in spring catchment, and the ease of solubility of carbonate rocks. The results of this study are of great significance for predicting the groundwater level and salinity of karst aquifer and ensuring the safety of drinking water in Jinci spring catchmen

Elevated fluoride concentration levels in rural villages of Siddipet, Telangana State, South India

Fluoride beyond desirable amounts(0.6–1.5 mg/L) in groundwater is a major problem and fluorosis is a very dangerous and deadly disease affecting millions of people across the World (Bell and Ludwig, 1970; Adimalla and Venkatayogi, 2017; Narsimha and Sudarshan, 2013, 2017a, 2017b) [1–5]. The investigated area is located in north-eastern part of Medak district, Telangana state and fluoride concentration in groundwater samples was measured by ion selective electrode method and its ranges from 0.4 to 2.2 mg/L with a mean value of 1.1 mg/L. Therefore, fluoride concentration data advised to the village people are consume drinking water which has less than 1.5 mg/L fluoride to avoid further fluorosis risks. Keywords: Groundwater quality, Fluoride contamination, Siddipet region, Telangana Stat

Drinking water pollution with respective of fluoride in the semi-arid region of Basara, Nirmal district, Telangana State, India

Fluoride is an essential microelement for human health. Statistically, smaller quantities (1.5 mg/L) to fluoride can give rise to a number of adverse effects, including dental fluorosis, skeletal fluorosis, increased rate of bone fractures, decreased birth rates, increased rate of urolithiasis (kidney stones), impaired thyroid function, and impaired development of intelligence in children [1–5]. The data suggested that the north-eastern part of the Basara region having high fluoride concentration, which is unsuitable for drinking purposes. Hence, this unsuitable drinking water cause fluorosis in this Basara and surrounding villages, and especially based on the findings suggests, where the fluoride levels are in below maximum permissible limits that water ingests to the people to avoid further fluorosis

Hydrogeochemical characterization and assessment of water suitability for drinking and irrigation in crystalline rocks of Mothkur region, Telangana State, South India

Abstract The present study confers the chemical quality of groundwater and surface water of Mothkur region, Telangana State, for drinking and irrigational purposes. Mothkur region is geologically occupied by the Archaean crystalline terrain. Most of the population depends on groundwater for their daily needs especially for drinking, house needs and irrigation purposes. For this reason, twenty-five groundwater and five surface water samples were collected and analysed for pH, electrical conductivity, total dissolved solids (TDS), total hardness (TH) bicarbonate (HCO3 −), chloride (Cl−), sulphate (SO4 2−), fluoride (F−), calcium (Ca2+), magnesium (Mg2+), sodium (Na+) and potassium (K+). The results are evaluated and compared with WHO and BIS water quality standards. Based on obtained results 32%, 20%, 28% and 4% of groundwater samples are not recommended for drinking with reference to the concentrations of fluoride, TDS, TH and Cl−, respectively. Base-exchange indices and meteoric genesis indices classified 67% and 33% of the water sources as the Na+–HCO3 − type and deep meteoric water percolation type, respectively. Piper trilinear diagram for geochemical classification indicates 44% and 60% of groundwater and surface water samples of Ca2+–Na+–HCO3 − type and 29% belong to Na+–HCO3 − types. Multivariate graphical methods have been carried out using the United States Salinity Laboratory diagram, Wilcox diagram, sodium adsorption ratio, per cent sodium (%Na), residual sodium carbonate and permeability index which indicate that majority of groundwater samples are useful for irrigation purposes