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Reinforced Concrete
Published in Fiona Cobb, Structural Engineer’s Pocket Book, 2020
Water Water is added to create the cement paste which coats the aggregate. The water/cement ratio must be carefully controlled as the addition of water to a mix will increase workability and shrinkage, but will reduce strength if cement is not added.
Concrete Mix Design
Published in M. Rashad Islam, Civil Engineering Materials, 2020
Regarding aggregate, the larger the aggregate-cement ratio, the larger the strength attained for a particular water–cement ratio. This is because if the paste represents a small proportion of the volume of the concrete, then the total porosity of the concrete is lower, and hence, its strength is higher. Smooth aggregate shows cracking at a lower stress than the rough and angular aggregate. Thus, concrete with angular aggregates has a higher flexural strength than that with rounded aggregates. However, the rounded aggregates require less water to attain certain workability than do the angular aggregates. Therefore, both types of aggregates are considered to have similar flexural characteristics.
Understanding Reinforced Concrete
Published in Ashwani Bedi, Ramsey Dabby, Structure for Architects, 2019
The ratio of water to cement (termed water-cement ratio) is normally between 0.4 and 0.5 ensuring that adequate water is present for the complete hydration of the cement, and for the proper workability (Figure 10.4).
High-performance self-compacting concrete with recycled coarse aggregate: comprehensive systematic review on mix design parameters
Published in Journal of Structural Integrity and Maintenance, 2023
Ahmad Alyaseen, Arunava Poddar, Hussain Alahmad, Navsal Kumar, Parveen Sihag
Consequently, RCA’s potential in the concrete industry is constrained by several technological challenges. When evaluating recycled aggregate quality, it is crucial to remember that each RCA particle is still aggregate of recycled concrete having natural coarse aggregate (NCA) and attached adhered mortar (AM) around them. RCA is the result of combining old concrete fragments with a new matrix. Separate identification of the components of these composite particles is required for thorough comprehension and standards of the RA and for making predictions about its potential impacts on concrete (Makul et al., 2021; Nagataki et al., 2004; Peng et al., 2020; Silva et al., 2017). It is hypothesized that the qualities of the RCA, the mix design, the mixing method, and the state of deterioration of the RCA contribute to the final product’s quality. The mechanical attributes of RCA are often the emphasis of all research on the usage of RCA. It is an adopted concept that although it is conceivable to use RCA as an NCA, using it will often cause a reduction in RCA strength. Thus, it is a circumstance that could be handled by raising the amount of cement, changing the water–cement ratio, adding supplementary cementitious materials (SCMs) to the mixture, etc. (Gonzalez-Corominas et al., 2017b; Guo et al., 2022b; B. Masood et al., 2020; T. Masood & Sonntag, 2020; Muduli & Mukharjee, 2020).
Characterization and prediction for the strength development of cement stabilized dredged sediment
Published in Marine Georesources & Geotechnology, 2021
Xiao Cheng, Yonghui Chen, Geng Chen, Bingyi Li
Horpibulsuk et al. (2005) found that W/C is a microstructure parameter, which takes into account the influence of moisture content in the mixture on the micro-fabric and the cement content required for cementing clay particles. Similar parameters are often seen in concrete and cement mixing pile projects. The water/cement ratio in concrete which is the amount ratio of water to cement, is the main parameter determining strength, durability, and a series of other major physical and mechanical properties of concrete. Clay-water/cement ratio can reflect the degree of hydration reaction in clay, which is introduced for analysis in this study, and expressed by Eq. (1): where W/C is the mass ratio of water in the clay sample to dry cement powder, is the mass of water in the clay, is the mass of dry cement added to the clay, is the natural moisture content of the clay (the mass ratio of water to dry clay) before adding cement, and is the mass of cement powder to wet clay. The W/C was calculated, ranging from 4.35 to 28.57.
Utilization of waste paper ash as supplementary cementitious material in C-25 concrete: Evaluation of fresh and hardened properties
Published in Cogent Engineering, 2021
A certain minimum quantity of water is required to be mixed with cement to ensure a complete chemical reaction between water and cement. Less water than this quantity would lead to an incomplete chemical reaction, thus resulting in the reduction of strength. Also, more water would increase the water-cement ratio and so would reduce its strength. The correct proportion of water to cement is required to achieve proper strength while using cement in structure. To get the proper amount of water, a normal consistency test of blended cement pastes was carried out. The normal consistency of blended pastes containing WPA is shown in Figure 1. The control paste or the paste without WPA had a normal consistency of 29%. All the pastes containing WPA showed normal consistency higher than the control paste. The usual range of water to cement ratio for normal consistency is between 26% and 33% (Sumit & Raut, 2013). The pastes with replacement up to 10% showed consistency within this range; however, after 10% replacement the results showed higher values of consistency.