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Construction of Concrete Pavements
Published in Rajib B. Mallick, Tahar El-Korchi, Pavement Engineering, 2017
Rajib B. Mallick, Tahar El-Korchi
Mixing is the process of mixing all the ingredients thoroughly without overloading the equipment above its capacity. When a concrete is adequately mixed, it should have a uniform appearance, with all ingredients uniformly distributed. And when samples are taken from different portions of a batch, they should have the same slump, density, air content, and coarse aggregate content. In a central mix concrete plant, the ingredients are batched into a stationary mixer. The mixer then completely mixes the components before discharging the concrete into a delivery vehicle for transporting to the paving site. The delivery vehicle can be a truck mixer operating at low mixing speed, a truck agitator, or a non-agitating flatbed truck. A shrink-mixed concrete is partially mixed in a stationary mixer, transported, then mixing is completed during delivery in a truck mixer. A truck-mixed concrete is mixed entirely in the truck mixer during the delivery to the site.
Construction methods for the first large RCC dam in Iran
Published in L. Berga, J.M. Buil, C. Jofré, S. Chonggang, Roller Compacted Concrete Dams, 2018
A.M. Azari, R. Peyrovdin, F. Ortega
The concrete plant has nominal capacity of 2 × 160 m3/hour, and consists in two plants each with two 2,25 m3 capacity horizontal twin-shaft batch type mixers. The cooling plant combines a water chiller plant to cool the mixing water down to 4°C and a flake ice plant with a total capacity of 180 tonne of ice per day. Theoretically the capacity of the ice plant could be less than that if placement would concentrate during the wintertime, but a larger one has been estimated to allow for some flexibility of the construction programme. The ice plant is completed with two 50-tonne capacity regulating ice storage bins.
Composite Processing
Published in Zainul Huda, Manufacturing, 2018
Concrete is a composite made by using cement, aggregate (sand or gravel), water, and additives. The manufacture of concrete involves mixing and blending of cement and aggregates, admixtures (chemical additives), any necessary fibers, and water. A ready-mix concrete plant consists of silos that contain cement, sand, gravel, and storage tanks of additives such as plasticizers, as well as a mixer to blend the components of concrete. For normal concrete, the ranges by absolute volume of the major components are presented in Table 15.1.
Environmental life cycle assessment of coarse natural and recycled aggregates for concrete
Published in European Journal of Environmental and Civil Engineering, 2018
Bruno Estanqueiro, José Dinis Silvestre, Jorge de Brito, Manuel Duarte Pinheiro
When aggregates reach the concrete plant, they are mixed with the other raw materials (cement, water, chemical additives), to obtain concrete. The environmental impacts of concrete production at the plant were excluded from the calculation because they are considered equal in the three scenarios.