Evaluation of selected basalts from Nigde, Turkey, as source of concrete aggregate

WOS: 000224871700005Basaltic rocks have been widely used as aggregate for various purposes. They show a variety of textural and mineralogical characteristics that may affect their physico-mechanical properties as well as their use as construction material. The study presented in this paper was carried out on basalts that are widespread in the Middle Anatolian Region of Turkey and that comprise the major source of local crushed rock aggregates. To determine the suitability of the basalts as alternative aggregate resource, Early Quaternary Melendiz Volcanites, Quaternary Karatas volcanites and Igredak basalts were selected around the Nigde Region. The experimental studies were conducted on these rocks. The samples were collected as being representative of 11 different types of basalt. The physico-mechanical properties of the basalts of different compositions and textures, and the properties of their aggregates were determined. The results were then compared with the typical acceptance limits in international usage. Although olivine basalts have better aggregate quality compared to other basalts, most of the basalts were found to be suitable for production of crushed rock aggregates for concrete production. (C) 2004 Elsevier B.V. All rights reserved

Evaluation of selected basalts from the point of alkali-silica reactivity

WOS: 000227638100011Basaltic rocks are potential rocks for alkali-silica reaction (ASR). The objective of this study is to determine reactivity of the basalts of different compositions and textures. The study was carried out on basalts that are widespread in the Middle Anatolian Region of Turkey. They form the major source of local crushed rock aggregates. Early Quaternary Melendiz volcanites, Quaternary Karatas volcanites and Igredag basalts were selected around the Nigde Region, and the experimental studies were conducted on these rocks. The samples were collected as being representative of I I different basalt types. The basalts were firstly classified according to their petrographical and chemical composition. Petrographic techniques and accelerated mortar bar test were then used to evaluate the potential alkali reactivity of the basalt aggregates. The basalts having acidic-intermediate character and matrix that is mainly composed of volcanic glass are potentially suitable for alkali-aggregate reaction (AAR) according to the standard values. (c) 2004 Elsevier Ltd. All rights reserved

Toxic gas emissions from the Kayseri peat deposit, central Anatolia, Turkey

WOS: 000311002300014Toxic gases evolving from the soil in urbanized peatland regions constitute a serious hazard since buildings may be subject to the direct ingress of volatiles into the structures. Peat formed in swamp and rarely exposed to subaerial conditions has been associated with the development of the folded foreland of the Quaternary Kayseri pull-apart basin. The peat deposit is extensively urbanized but so far no studies have evaluated the extent of the ground gas hazard. In this paper, the geology, petrography and chemical variation of the Kayseri peat deposit have been studied in order to predict the public health risk from the land gases' behaviour, especially in soil gases. The main volatile species detected are methane (CH4), hydrogen sulphide (H2S) and carbon dioxide (CO2), all of which are highly toxic. The primary means of gas entry is directly from the ground through the floors, walls, and especially subsurface telephone cable pipes. Indoor vents emit 1000-70,000 ppm CH4, 330-49,000 ppm CO2 and 3.8-6.5 ppm H2S in soil and subsurface pipes; concentrations high enough to present an acute respiratory hazard to persons close to the vents

Atmospheric and anthropogenic deterioration of the Ivriz rock monument: Eregli-Konya, Central Anatolia, Turkey

WOS:000620118900001The aim of this study is to determine the extent of deterioration of the limestone on which the Ivriz rock monument is engraved. This monument is near Aydinkent (Ivriz) village and located 12 km from the Eregli district of Konya. The height of the Ivriz Hittite monument is 4.20 m and its width is 2.40 m. It dates back to the second-half of the eighth century BC. The rocks on which the reliefs are engraved are limestone; the lower parts are brecciated with open cracks, and the upper parts show fewer cracks with smaller gaps. To enable the identification of the characteristics of the rocks on which the figures are located, non-destructive methods were used. Surface humidity, P wave velocity, thermal imaging, and Schmidt hardness measurement were applied to the wall surface of the monument, and mapping studies were conducted. Surface humidity varied between 26 and 58% with the highest values measured in the sections where the cracks are densest. The P wave velocity measured at the rock monument varied between 1.6 and 5.8 km/s, with the lowest values found in the sections where cracks were denser. Schmidt rebound values varied between 18 and 42, with higher values obtained in those sections with fewer effects of deterioration. According to the detailed observations and data obtained from non-destructive techniques (NDT) and laboratory data, the most significant deterioration has resulted from atmospheric conditions and damage by humans. The most common effects of degradation in this area are erosion by water, granular disintegration, cracks, microkarst, black crust, biodegradation (lichen, algae, and higher plants), and vandalism

Variability of soil organic carbon stocks under different land uses: a study in an afro-montane landscape in southwestern Uganda

We explore and compare quantities and patterns of Soil Organic Carbon (SOC) in protected forest and neighboring land around Bwindi Impenetrable National Park (a mountain protected area in Southwestern Uganda). We assessed paired sites of natural forest and major land uses (potato, tea and grazing lands) converted between 1973 and 2010. These pairings were replicated at three altitudinal zones. Plots (20 m by 50 m) were demarcated within each site. Five composite soil and core samples were obtained from 0 to 15 cm (top-soil) and 15–30 cm (sub-soil) at each plot. In total, 192 composite soil and core samples were collected. Within forest we found marked site to site variation in SOC from 54.6 to 82.6 Mg/ha. There was a tendency for higher SOC in converted land, associated with higher bulk density suggesting quality based land use selection with forest left on inferior soils. Cultivation, landscape position, slope and sampling depth were all significantly (P \u3c 0.05) related to variation in SOC stocks following forest conversion but time since conversion had no detectable impact. Interestingly, there was no significant relationship between SOC in the top and sub-soils. Higher SOC is largely determined by higher bulk density. The large SOC stocks in these afro-montane soils are less predictable and more persistent than anticipated