Concrete is a favoured building material due to its ease of production and use. Even though the concrete mix is designed to have a uniform strength throughout the entire member, casting, as well as the basic characteristics of the concrete materials, could yield a non-homogeneous constitution, resulting in a concrete strength gradation as a function of the depth of the member. A functionally continuous and smooth strength gradation of the concrete member along its axis or section is defined as graded concrete. The objective of this research is to analyse the influence of two different concrete compressive strengths that composed the graded concrete member. The study is split into two parts: the experimental work describing and identifying the mechanical properties of functionally graded concrete and the finite element analysis implementing these property variations in a model. The results showed that the concrete gradation influenced the ultimate strength of a member negatively and altered the stress distribution and displacement response of the specimen.

Abstract. The Architecture, Engineering and Construction (AEC) industry is known as one of the prominent sectors contributing to economic stability in Indonesia. On the other hand, this sector is also responsible for significant environmental impact in the country. Building Information Modelling (BIM) is a key innovative technology enabling advanced management within the construction and civil engineering industries and facilitating improvements in sustainability and asset management across the globe. BIM enables the achievement of three sustainable dimensions which are known as Triple Bottom Line (TBL). However, to enable the construction industry in Indonesia to expand and adopt this new engineering technology, the scarcity of the experts in BIM remains a barrier to initiate the migration from traditional management to BIM. From 40 respondents who participated in this study, only 2 respondents had competence in BIM. However, the awareness rate of Indonesian engineers about BIM is actually quite good with 67.5% of respondents having recognised BIM, although mostly with limited or basic knowledge. This research also defines BIM's impact to sustainability aspects in construction.

No abstract

Dry concrete is a cementitious material, consisting of aggregates imbedded in a cement matrix. The water cement factor is customary kept low, the compression stress is given to reduce the air voids in the mixture, to enable the entrapped water to optimize the hydration process, and to create more dense material so it will provide a better performance. This study uses 2 types of mix designs and 9 types of compressive stress. The experimental test showed that the greater compressive stress given duri ng the production process increase the compressive strength of the dry concrete until it reaches the optimum point.

Snail shell is an abundance of waste in Indonesia, particularly from snail or Achatina fulica snail. Snail shell has high calcium content; thus, it can be used as an alternative replacement for CaO/CaCO3. This research aimed to make CaCO and CaO from the Achatina fulica snail shell waste as the base material of hydroxyapatite. The synthesis process of CaO/ CaCO3 used the ball milling method for 6 hours in various sintering temperature of 850 °C, 950 °C, 1050 °C. The synthesised samples were then characterized using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM-EDX) and Fourier transform infrared (FTIR). The XRD results showed the successful synthesis of snail shell waste into CaCO3 and CaO with the smallest particle size from each temperature variation were 17.60 nm, 30.16 nm, and 53.30 nm. The SEM images showed agglomeration and porosity in all samples. The EDX test results displayed the highest Ca (calcium) was found in the sample with 1050°C sintering temperature, and the highest O (oxygen) level was found in the sample with 850 °C sintering temperature. The FTIR test results presented the functional group transformation from CaCO3 into higher CaO along with the increase of the sintering temperature.