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Activated Low Clinker Slag Portland Cement and Concrete on Its Basis
Published in Leonid Dvorkin, Vadim Zhitkovsky, Mohammed Sonebi, Vitaliy Marchuk, Yurii Stepasiuk, Improving Concrete and Mortar Using Modified Ash and Slag Cements, 2020
Leonid Dvorkin, Vadim Zhitkovsky, Mohammed Sonebi, Vitaliy Marchuk, Yurii Stepasiuk
Foam concrete is a composite material obtained by mixing aqueous solution of binders and foam. The quality of the foam concrete depends directly on the raw materials used and the structure that is formed directly during its preparation and during curing [72]. The foam concrete quality is significantly influenced by the fineness of grinding of the binder used [73]. Increasing the cement fineness of the grinding should contribute to the formation of a more homogeneous interstitial partitions and, therefore, a better structure of the foam concrete [73].
Portland Cement Concretes
Published in M. Rashad Islam, Civil Engineering Materials, 2020
Lightweight concretes are often used for high thermal insulation, but little in structural requirement areas. Foamed concrete is a highly workable and low-density material which can incorporate up to 50% entrained air. It has self-leveling, self-compacting, and ‘pumpability’ properties. Foamed concrete is ideal for difficult-to-access sewer systems, pipelines, and culverts. It is also good for the reinstatement of temporary road trenches. As mentioned, foamed concrete is used for thermal insulation, and thus suitable for sub-screeds and filling under-floor voids. The benefits of using lightweight aggregate concrete include: Reduction in dead loads, providing savings in foundations, reinforcement, and formworkImproved thermal insulationsImproved fire resistanceEasy transporting and handling
Lime, cement and concrete
Published in Arthur Lyons, Materials for Architects and Builders, 2019
Foamed concrete or mortar contains up to 80% by volume of void space, with densities as low as 300 kg/m3 and 28-day strengths between 0.2 and 20 MPa. It is typically produced by blending cement, fine sand or fly ash and water into a preformed foam or by mechanically foaming the appropriate mix using a foaming surfactant. For the low densities below 600 kg/m3, no fillers are included, but for densities up to 1600 kg/m3 limestone dust and concreting sand may be incorporated. Foamed concrete is free-flowing, can be pumped and requires no compaction. When set, the material offers good frost resistance and thermal insulation. It is therefore used for trench reinstatement, filling cellars or to provide insulation under floors or in flat roofs.
Mechanical properties and constitutive model of fibre-reinforced high-performance class-F fly ash foam concrete
Published in European Journal of Environmental and Civil Engineering, 2023
Yunhong Hao, Lida Qin, Xiaoyan He, Hao Sun, Zhuoxuan Wu, Yongli Hou
The contradiction between building energy consumption and energy environmental constraints has become increasingly prominent. Countries around the world have begun to vigorously implement building energy-saving policies, advocate environmentally friendly, resource-saving green buildings and develop a low-carbon economy (Görhan & Kavasoğlu, 2022; Guo et al., 2022). Therefore, new environmentally friendly building materials with lightweight, high-strength, green and energy-saving characteristics are of great significance to the construction industry, which consumes considerable amounts of energy (Arenas et al., 2022). Foam concrete is a lightweight concrete material with a large number of bubbles inside, which is mixed and cured by mixing cement, water and foaming agents with cement as a cementing material (Youssef et al., 2018). As a representative of lightweight concrete, foam concrete stands out from many energy-saving and environmentally friendly materials owing to its unique structure, low cost and non-combustive characteristics (Falliano et al., 2018).
Field assessment of a subgrade-culvert transition zone constructed with foamed concrete in the ballasted railway
Published in International Journal of Rail Transportation, 2023
Zhichao Huang, Qian Su, Junjie Huang, Xuzhen He, Yanfei Pei, Chen Yang
As a kind of lightweight concrete, according to results of indoor material tests [7–16], foamed concrete has been confirmed that it has both good physical and mechanical properties. To be specific, based on the engineering requirements, generally the density of foamed concrete can be controlled at 400–1000 kg/m3, while the figure for granular earth – rock materials is about 1700–2000 kg/m3. Besides, the compressive strength of foamed concrete without any additives is about 0.5–40 MPa normally, and the figure for that with hybrid materials or chemical materials can up to more than 120 MPa. Thus it can reduce the additional stress on the ground and then decrease the transition section subgrade settlement by filled with foamed concrete. Also it can improve the rigidity of the transition section subgrade and reduce rigidity difference between the subgrade and frame culvert, resulting in reduce the dynamic response of the rail. Actually foamed concrete has been already used in different engineering such as filled the widened road subgrade, the abutment back of the highway, and the new roadbed adjacent to the existing structure [17–19]. And then based on those previous engineering experience and research studies, foamed concrete gradually has been used in rail engineering construction such as subgrade widening of Dezhou West Railway Station (in Shandong province, China) and subgrade widening of Xinzhou West Railway Station (in Shanxi province, China), as shown in Figure 3.
Instantaneous and long-term performance of foamed concrete slabs
Published in European Journal of Environmental and Civil Engineering, 2022
Foamed concrete is made from cement, water, sand, polypropylene (PP) fibers, foam, and superplasticizer. Pozzolana Portland cement produced at Manaseer Group in Jordan is used and its chemical composition is presented in Table 1. As no coarse aggregate is used, only fine aggregate (sand) is used according to ACI 523.3R-93 (1993) that allowed using sand conforming to ASTM C144 to produce foamed concrete. The PP fibers can be used to reduce shrinkage and control cracking (Abdulridha et al., 2021; Aire et al., 2011; Banthia & Gupta, 2006; Dahl 1998; Islam & Gupta, 2016; Soroushian et al., 1993). Moreover, Madhavi et al. (2014) presented a comprehensive review on PP fiber reinforced concrete, and it was concluded that the mechanical properties of concrete that contains PP fibers were improved including the tensile strength, flexural strength, toughness, and impact strength. Kuranlı et al. (2022) and Jameel et al. (2022) stated that PP fibers improved the mechanical properties, such as compressive and tensile strength of concrete under high temperatures compared to mixtures without PP fibers at the same temperature level.