PurposeBuilding information modeling (BIM) is a process of creating an intelligent virtual model integrating project data from design to construction and operation. BIM models enhance the process of communicating the progress of construction to stakeholders and facilitate integrated project delivery, coordination and clash detection. However, barriers within the construction industry in Ethiopia has led to slow BIM adoption in the country. The aim of this paper is to identify perceived BIM barriers, provide a platform to quantify their importance and develop a regression model to link individual's personal/professional attributes to their perception of BIM barrier.Design/methodology/approachTo address the objectives of this research, an online survey was developed to collect feedback from construction professionals in Ethiopia on 20 major adoption barriers extracted from a thorough review of literature. Relative importance index and strength of consensus metric were employed to identify the significance of barriers. This was then succeeded by performing exploratory factor analysis to determine the major constructs of BIM barriers which was then used to develop a multivariate regression model linking respondents' personal attributes to their perception of BIM barrier.FindingsResults revealed the importance of project complexity and BIM maturity level in prioritizing barriers that are more relevant under various contexts. More specifically, results indicated the following study highlights: Project complexity led to higher perceived weights for lack of appropriate physical/cloud infrastructures, and a BIM standard. Higher levels of BIM maturity signified the importance of BIM internal issues such as liability, licensing and maintenance issues among other adoption barriers. Female participants tended not to consider intangibility of BIM benefits as a major barrier towards BIM adoption compared to male participants. Age of the participants turned out to be the least important factor in their prioritization of BIM perceived adoption barriers.Originality/valueWhile many research studies have explored BIM adoption barriers in various countries around the world, none to the best of the authors' knowledge have attempted to develop a model to highlight the impact of individuals' personal/professional attributes on their perception of adoption barriers within their community which can help with prioritizing the barriers that are deemed to be more important given the characteristics of the community under study. Our result indicated the importance of BIM maturity level and project complexity in prioritizing barriers associated with BIM adoption within Ethiopia's construction industry.

As a result of a change in the living standards and an accelerated rate of urbanization, the construction industry is booming globally.The construction industry is among the most prosperous economic sectors around the world as it transforms various resources into the constructed infrastructure necessary for socio-economic development. Despite the relevance to the socio-economic growth, it's also recognized that construction activities and the natural environment are interconnected [1]. Lately, waste generation due to demolition has become an essential issue with possible negative impacts on the environment. There is a large amount of construction and demolition (C&D) waste generation due to: new zoning bylaws, modified settlement patterns, increased population in urban areas due to industrial development, modernization of old road, and bridges for the present as well as for future growing traffic, and during renovation and demolition of existing buildingEthiopia is experiencing problems, of rapid population growth rate, lack of education amongst the population, uncontrolled rapid urbanization, affordable housing shortages, and erosion. Along with most of the African cities, Ethiopian cities don't have the spatial, physical, and socio-economic requirements fundamental to sustain the livelihood of the city. To address the problems, the Ethiopian government has been implementing transformation plans and low -cost housing programs [3,4]. These programs were launched during different phases according to the agreements reached such

No abstract

The increase in the demand for concrete production for the development of infrastructures in developing countries like Ethiopia leads to the depletion of virgin aggregates and high cement demand, which imposes negative environmental impacts. In sustainable development, there is a need for construction materials to focus on the economy, efficient energy utilization, and environmental protections. One of the strategies in green concrete production is the use of locally available construction materials. Scoria is widely available around the central towns of Ethiopia, especially around the rift valley regions where huge construction activities are taking place. The aim of this paper is therefore to analyze the suitability of scoria as a fine aggregate for concrete production and its effect on the properties of concrete. A differing ratio of scoria was considered as a partial replacement of fine aggregate with river sand after analyzing its engineering properties, and its effect on the mechanical properties of concrete were examined. The test results on the engineering properties of scoria revealed that the material is suitable to be used as a fine aggregate in concrete production. The replacement of scoria with river sand also enhanced the mechanical strength of the concrete. Generally, the findings of the experimental study showed that scoria could replace river sand by up to 50% for conventional concrete production.

His teaching and research areas include Building Information Modeling and a variety of research studies in the field of infrastructure management.

Today researchers all over the world are focusing on ways of utilizing either industrial or agricultural wastes as a source of raw materials for the construction industry. This is used to minimize the emission of CO2 during the manufacturing of cement. One of the agricultural waste products is coffee husk which is found in large amounts in Ethiopia. This paper aims to characterize the physical and chemical properties of Coffee Husks Ash (CHA) by using X-ray diffraction (XRD), Scanning electron microscope (SEM), and Fourier Transforms Infrared Spectroscopy (FTIR) tests, and also the experiment were conducted to determine the compressive, split tensile and flexural strength of the material and durability tests were determined. The result have shown that, when the replacement percent further increases, the crystalline material increases, silicate concentration decreases, and also the micro pores or air void are increases, which may lead to decreasing the strength of concrete. In the case of mechanical property of concrete, there has been remarkable increment up to 5% CHA replacement and also strongly satisfied up to 10% replacement, furthermore increasing CHA replacement up to 20% are optimum dosage of normal concrete mix production of C-25 concrete. Finally, water absorption and sulfate attack of partially replaced concrete is shown as an improvement in the durability of concrete.

Theoretical models based on modern interpretations of the morphology and interactions of cement hydration products are developed for prediction of the mechanical properties of hydrated cement paste (hcp). The models are based on the emerging nanostructural vision of calcium silicate hydrate (C-S-H) morphology, and account for the intermolecular interactions between nano-scale calcium C-S-H particles. The models also incorporate the effects of capillary porosity and microcracking within hydrated cement paste. The intrinsic modulus of elasticity and tensile strength of hydrated cement paste are determined based on intermolecular interactions between C-S-H nano-particles. Modeling of fracture toughness indicates that frictional pull-out of the micro-scale calcium hydroxide (CH) platelets makes major contributions to the fracture energy of hcp. A tensile strength model was developed for hcp based on the linear elastic fracture mechanics theories. The predicted theoretical models are in reasonable agreements with empirical models developed based on the experimental performance of hcp.

No abstract