Research on the reuse of waste materials in the concrete industry has been quite intensive in the past decade. The objective of this research is to identify the performance of oven-dried eggshell powder as a partial cement replacement in the production of concrete under both water-cured and air-cured regimes. Eggshell powder of various amounts, namely 5%, 10%, 15% and 20% by volume, was added as a replacement for ordinary Portland cement. The results showed that water-cured eggshell concrete greatly improved the compressive and flexural strength of concrete, by up to 51·1% and 57·8%, respectively. The rate of water absorption of eggshell concrete was reduced by approximately 50%, as eggshell powder filled up the existing voids, making it more impermeable. However, the compressive strength of the eggshell concrete decreases gradually when the amount of eggshell powder increased, during immersion in acid and alkali solutions, because eggshell contains a high amount of calcium, which reacts readily with acid and alkali solutions. As the eggshell content increases, the solution reacts with the paste so the bonding of the paste reduces, and therefore the strength also reduces. The reduction of compressive strength during immersion in sulphuric solution and sodium sulphate solution was 27·5% and 31·2%, respectively, when 20% eggshell powder was used to replace cement. It can be concluded that the optimum percentage of oven-dried eggshell powder as a partial cement replacement is 15%.

Construction is a critical sector of any economy in terms of value production, labor, and contributing to the gross national product. Managing risk is a relatively young area in Yemen’s construction sector, but it is gaining traction as building activity and competition rise. Construction firms mitigate risk by using a variety of risk management methods. Therefore, there is a need to assess these procedures in order to detect shortcomings. This research aims to establish the existing risk management strategies used in Yemeni building projects. Survey questionnaires were used to collect data. Respondents were drawn from Yemeni construction businesses. Risk management is not executed systematically, intentionally, or continuously, and most firms’ risk management procedures are reactive, semipermanent, informal, and unstructured, with no or few dedicated resources to address risks. This strategy is inconsistent with generally accepted risk management principles. Nonetheless, the findings suggest a general understanding of risk management and a willingness to learn from previous errors. The study of the findings suggests that risk identification approaches such as judgment and historical data are employed for risk analysis, and that the industry typically attempts to avoid or transfer risks in Yemeni building projects. The results shed light on the shortcomings of Yemen’s project management practices. To guarantee that construction projects obtain maximum value for money, project managers of big construction businesses in Yemen need a strong understanding of and training in globally accepted systematic risk management procedures. Finally, this study can help future stakeholders determine how to work together to manage risk.

In the construction industry, risk management concept is a less popular technique. There are three main stages in the systematic approach to risk management in construction industry. These stages include: a) risk response; b) risk analysis and evaluation; and c) risk identification. The high risk related to construction business affects each of its participants; while operational analysis and management of construction related risks remain an enormous task to practitioners of the industry. This paper tends towards reviewing the existing literature on construction project risk managements in developing countries specifically on risk management process. The literature lacks ample risk management process approach capable of capturing risk impact on diverse project objectives. This literature review aims at discovering the frequently used techniques in risk identification and analysis. It also attempts to identify response to clarifying the different classifications of risk sources in the existing literature of developing countries, and to identify the future research directions on project risks in the area of construction in developing countries.

The impacts of highway construction delays are not limited to the construction industry, but also affect the nation’s overall economic and social conditions. One factor that can cause delays is the project team rushing into construction without assessing the project’s readiness. In other words, adequately assessing the readiness of a project before construction may prevent delays. Therefore, this study aims to identify key decision criteria (KDC) to assess the construction readiness of highway projects. To achieve this objective, 109 surveys completed by industry practitioners were analyzed using the mean ranking technique, normalization method, agreement analysis, and factor analysis. A total of 18 KDC for assessing the construction readiness of highway projects were identified. In addition, the underlying categories for the KDC were reduced uncertainties, availability of resources, approvals and permits, and adequate traffic management plans. This study contributes to the current body of knowledge by identifying a list of KDC for the construction readiness of highway projects. This study’s practical contribution is the list of KDC that industry practitioners can use to assess the readiness of highway projects 1prior to construction.

Highways are often high-risk projects due to its importance to a nation’s economic, societal, and political development. Therefore, highway projects need to be successful. Numerous researchers have identified the key factors affecting their local highway projects to identify opportunities for improvements. However, the current body of literature lacks that type of information in regards to Malaysia’s construction industry. This study’s objective is to identify factors that are affecting Malaysia’s highway projects from industry practitioners’ perspective. To achieve this objective, interview data with highway project managers are analyzed. Eleven factors affecting the success of highway projects in Malaysia were identified. The factors are: workflow for the design process, competencies of project managers, availability of workforce, availability of materials, availability of equipment, weather, site location, involvement from upper management, support from clients, public acceptance, and efficiency of authorities. This study contributes to the current body of knowledge by providing researchers and practitioners with a set of alternative factors that are affecting highway project success. The lesson of this study would help the industry to promote project success of highway projects in Malaysia.

In the building domain, the non-renewable resource of sand is widely used to produce concrete and mortar. The sand production has been estimated to be more than 10 billion tons with a total of 1.2 billion tons used in concrete in the last decade, which causes the gradual reduction of available building materials and impacts the environment. Since there are abundant desert sand resources in northwestern China, it would be viable to utilize desert sand as an alternative material for concrete production. In this study, an investigation of dynamic mechanical behaviors of desert sand concrete (DSC) was conducted. Various desert sand replacement ratios (0–100%) were used to replace the equivalent hill sand as fine aggregate. Experimental results showed that strain rate had a strong effect on the dynamic mechanical behaviors of DSC. The compressive strength (at room temperature) and flexural strength (after elevated temperature) increased with desert sand replacement ratio (DSRR) with the optimum replacement ratio of 40%, which was because the increase of DSRR improved the compaction of DSC. However, the effect of the low strength of desert sand was higher than that of the compaction when the DSSR exceeded 40%, so both strength values generally decreased with the increase of DSRR. Moreover, the dynamic constitutive model of DSC at room temperature was established on the basis of a nonlinear visco–elastic constitutive model (ZWT model), which can predict the stress–strain curves of DSC.