Recycled aggregates have been widely studied and used in concrete products nowadays. There are still many waste materials that can be used as recycled aggregates other than crushed concrete particles. This paper aims to study the property variations of sustainable concrete paving block incorporating different contents of construction wastes. Five different types of waste materials were used in this project, including: recycled concrete coarse aggregate (RCCA), recycled concrete fine aggregate (RCFA), crushed glass (CG), crumb rubber (CB), and ground granulated blast furnace slag (GGBS). According to the test results of the properties of blocks mixed with different levels of wastes materials, it is concluded that adding both RCCA and RCFA in the block can decrease its strength and increase the water absorption. The suggested replacement levels for RCCA and RCFA are 60% and 20%, respectively. Mixing crushed glass in the concrete paving blocks as a type of coarse aggregates can improve the blocks’ strength and decrease the blocks’ water absorption. Addition of crumb rubber causes a significant deterioration of blocks’ properties except for its slip resistance.
Ultra-high performance fibre reinforced concrete (UHPFRC) is an innovative cement-based engineering material. The mechanical properties of UHPFRC not only depend on the properties of the concrete matrix and fibres, but also depend on the interaction between these two components. The fibre distribution is affected by many factors and previous researchers had developed different approaches to test the fibre distribution. This research adopted the non-destructive C-shape ferromagnetic probe inductive test and investigated the straight steel fibre distribution of the UHPFRC plate. A simplified characterization equation is introduced with an attenuation factor to consider the different plate thicknesses. The effective testing depth of this probe was tested to be 24 mm. By applying this method, fibre volume content and the fibre orientation angle can be calibrated for the entire plate. The fibre volume content generally fulfilled the design requirement. The fibre orientation angle followed a normal distribution, with a mean value of 45.60°. By testing small flexural specimens cut from the plates, it was found out that the mechanical performance (peak flexural strength) correlates with the product of fibre volume content and cosine fibre orientation angle.
One of the most effective ways to improve building energy efficiency and consumption is to increase the thermal insulation of the building envelope and reduce the heat loss through walls. A new type of thermal insulation wall panel, consisting of a lightweight assembled exterior wall panel, was investigated in this research through experimental and numerical analyses. The feasibility of achieving the anticipated thermal performance through finite element modeling using ABAQUS® was verified. Good agreement between numerical simulation and experimental measurement was found, and the accuracy is 98.8%. To further reduce the heat transfer coefficient (U-value) of the panel to improve its thermal performance, parametric analyses were conducted utilizing the validated finite element model. The simulation shows that changing the insulation material is the best option, and the U-value reduction percentage reached 13.2%. Moreover, the combination of reducing the number of steel studs, decreasing the size of steel studs, implementing the opening of the light-gauge steel, and improving the insulation material led to a 23.7% reduction in the U-value at 0.695 W·m−2·K−1.
Recycled concrete aggregates have been widely studied and used in concrete products nowadays. However, other recycled wastes, such as glass, have not been involved too much in recycled aggregate concrete studies. This paper aims to study the impact of the content variation of the different recycled wastes to the properties of the concrete paving block. In this paper, not only recycled coarse concrete aggregates, crushed glass are also used as the recycled aggregate in the concrete paving block in different replacement levels. According to test the properties of blocks mixed with different recycled wastes, the experimental results indicate that: (1) adding recycled concrete coarse aggregate (RCCA) in the blocks can decrease the blocks’ strength, and increase the water absorption. The suggested replacement levels for RCCA is 60%; (2) mixing crushed glass (CG) in the concrete paving blocks as a type of coarse aggregates can obviously improve the blocks’ strength and decrease the blocks’ water absorption.