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Urban aquatic habitats: Characteristics and functioning
Published in Iwona Wagner, Jiri Marsalek, Pascal Breil, Aquatic Habitats in Sustainable Urban Water Management, 2014
Michael Lafont, Jiri Marsalek, Pascal Breil
In some climates, there are also intermittent streams (often described by such terms as arroyos, wadis or torrents), which flow only during a part of the year. Nevertheless these streams are also ecologically important and can be characterized by special biological assemblages (algae, bryophytes, invertebrates and amphibians) that are indicative of the degree of hydrologic permanence. Finally, there are also ephemeral streams, which form only during and after rainfall. A similar classification could be used for impoundments with intermittent water storage.
Acid resistance of fine bone china ceramic aggregate concrete
Published in European Journal of Environmental and Civil Engineering, 2021
Salman Siddique, Trilok Gupta, Akshay Anil Thakare, Vivek Gupta, Sandeep Chaudhary
For the past few years, studies have been carried out focusing on the acid resistant properties of concrete. Various authors have evaluated the acid resistance performance of concrete mixes containing alternative materials. Samimi, Kamali-Bernard, and Maghsoudi (2018) observed the acid resistance in self-compacting concrete mixes containing pumice and zeolite. They reported that addition of pumice and zeolite increases the resistance of concrete mixes against acid attack. They concluded that lowered permeability and stable phases of hydration products are the major reasons for higher resistance to acid attack. Alnahhal et al. (2018) investigated the acid resistant properties of recycled aggregate concrete containing rice husk ash, palm oil fuel ash and palm oil clinker powder as supplementary cementitious materials (SCM). They reported that addition of SCM in recycled aggregate concrete lowered the formation of calcium hydroxide which improved the concrete resistance to acid attack. Dash and Patro (2018) observed the effects of water cooled ferrochrome slag as fine aggregate on acid resistant properties of concrete. They reported that alkaline behaviour of slag neutralised the acid attack in the concrete matrix thereby increasing the acid resistant property of concrete. Ariffin, Bhutta, Hussin, Tahir, and Aziah (2013) reported that blended ash geopolymer concrete have higher acid resistance characteristics than traditional concrete. They observed that sodium aluminate-based binder system had little effect of acid as compared to calcium-based binder systems. Thandavamoorthy (2016) reported that utilisation of wood waste as coarse aggregate in concrete lowered the acid resistant properties of concrete. The increased porosity of concrete was the leading cause of the acid penetration in concrete. Leiva, Arenas, Vilches, Arroyo, and Luna-Galiano (2017) assessed the acid resistance of concrete containing bottom ash as aggregate. The addition of bottom ash aggregate was found to lower the resistance to acid attack due to the increased penetration of acid solution into the concrete matrix.