Lightweight concrete is a very useful and advantageous material in the modern civil industry. It is lighter than normal-weight concrete. This paper investigates the review of the significant applications and advantages of using lightweight concrete in the area of civil engineering. Also, therefore, the use of lightweight concrete has a great impact on developing countries as it permits design flexibility and substantial saving in the cost of construction. In this paper, the background for many experimental studies of lightweight concrete made with sawdust is provided and a comparison between these studies.

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Claims are one of the most important problems in construction projects that lead to conflicts between key stakeholders in the republic of IRAQ. Perhaps the main reason is the adoption of traditional systems in claims management, so the use of modern technologies in project management such as BIM technology can contribute to reducing these claims. The study aims to briefly shed light on the most important claims problems in Iraq, then this study attempts to address the claims problem through adopting BIM technology in developing a claims management prototype; This study highlighted 29 problems related to claims, and this model was evaluated by a group of experts and proved its efficiency in solving most of these problems. This study concluded that the model studied can contribute to addressing the problems of claims in Iraqi construction projects, and the results concluded for a set of research gaps that, if addressed, this model will become more accurate and comprehensive.

Due to the growth of the population, waste tires have a significant effect on the environmental issue. Every year, the decomposition of waste tire rubber is rapidly rising. Also, recycle rubber scraps into concrete production the main issue could be decreased. Recycle rubber scraps could be combined in concrete by substituting with fine and/or coarse aggregate. Decreasing the fine and coarse aggregate and preserving these natural materials. Furthermore, recycling the rubber scraps avoids the need for tire landfilling, as one of the main environmental problems of the future. A lot of investigation has suggested the use of alternative materials in concrete production, one such material that has gained a lot of attention is the recycled waste tire rubber. This study investigates of existing efforts of the literature studying recycled rubber scraps used as sand and gravel substituting in concrete production and its effect on numerous concrete characteristics.

Hollow Lightweight Concrete (HLC) beams are gaining popularity due to low cost and low weight as compared with the Solid Lightweight Concrete (SLC) beams. HLC and SLC beams decrease in weight, without losing strength and durability. Flexural and shear behavior of reinforced HLC and SLC beams made with sawdust under two-point load is investigated in this study. The ultimate deformation efficiency and shear resistant mechanism of HLC beams are discussed experimentally and compared with other SLC beams. The beams, tested in this research, are rectangular.Beams were designed and constructed as 12 * 23 * 100 cm. Six concrete beam models were prepared including three SLC beams without the hollow and the other three HLC beams poured hollow 50 * 7.5 cm throughout the all beam of 100 cm. All beams were split according to the distance between vertical stirrups, these stirrups were divided into three specimens 45, 13, and 6 cm. By analyzing six experimental test beams, in this research, investigated the effect of diverse factors on the shear of beams. On comparison with normal concrete beams, this work describes the failure of mechanism, process, and ductility. The first crack loads, ultimate loads, load-deflection behavior, crack patterns and shapes of failure were investigated in this study. The experimental results show the ultimate performance of HLC beams are pure shear and controlled by yielding tension and compression steel bars. Also, it is found that the measured size and configuration of the hollow opening had an effect on the load-carry capacity and mid-span deflection of HLC beams. Thus, the design and construction details of beams can be additionally customized to reduce the total cost and weight of the HLC beams.