A hybrid classification and evaluation method based on deep learning for decoration and renovation waste in view of recycling.

The escalating volume of decoration and renovation waste (D&RW) amid the rapid urbanization in China has posed significant challenges for the effective recycling of this waste stream, primarily due to the difficulty of accurately assessing its precise composition. To enhance the recycling of high-value materials from D&RW, a comprehensive understanding of its composition and quality is crucial before sorting. In this study, we propose a hybrid method that combines instance segmentation deep learning (DL) models with morphological machine learning (ML) models to automate the classification and evaluation of D&RW.

Experimental Study on Interfacial Shear Behavior of 3D Printed Recycled Mortar.

A novel shear test method on shear bond behavior of 3D printed interlayer interfaces and interstrip interfaces was proposed in this study. Thereafter, the effect of different replacement ratios of recycled sand, printing intervals, and surface treatments were investigated. The test results showed that under the same printing condition, the interfacial shear strengths of interlayer interface and interstrip interface were similar to each other.

Quantification of the Hardened Cement Paste Content in Fine Recycled Concrete Aggregates by Means of Salicylic Acid Dissolution.

Adherent hardened cement paste attached to recycled concrete aggregates (RCA) generally presents a higher porosity than natural aggregates, which induces a lower porosity in the properties of RCA. The characterization of the adherent hardened cement paste content () in the fine RCA would promote better applications of RCA in concrete, but the determination of in fine RCA is not well established. A simple method based on salicylic acid dissolution was specifically developed to quantify the in RCA, especially for RCA containing limestone aggregates.

Low-Carbon and Fundamental Properties of Eco-Efficient Mortar with Recycled Powders.

Using recycled powders from solid waste is accepted as an effective strategy to realize the sustainable development of the construction industry. In our study, the cement was substituted by two kinds of recycled powders, i.e.

Life cycle assessment of concrete structures with reuse and recycling strategies: A novel framework and case study.

In the construction industry, reuse and recycling strategies help reducing waste, saving energy and cutting down emissions by converting construction and demolition (C&D) waste into resources. This study proposes a novel framework to guide the life cycle assessment (LCA) of concrete structures with reuse and recycling strategies. The material flow in recycling strategies is clarified explicitly.

A 3D Printed Ready-Mixed Concrete Power Distribution Substation: Materials and Construction Technology.

Currently, 3D concrete printing technology is not yet able to print ready-mixed concrete with coarse aggregates. Based on an independently developed 3D printing construction equipment system and optimized concrete materials, a 3D concrete printer that can directly print ready-mixed concrete is developed. This paper introduces the whole 3D printing process for one power distribution substation in detail, including the printing equipment, key software, concrete preparation, printing process, and construction inspection.

Using Green Supplementary Materials to Achieve More Ductile ECC.

To improve the greenness and deformability of engineered cementitious composites (ECC), recycled powder (RP) from construction and demolition waste with an average size of 45 μm and crumb rubber (CR) of two particle sizes (40CR and 80CR) were used as supplements in the mix. In the present study, fly ash and silica sand used in ECC were replaced by RP (50% and 100% by weight) and CR (13% and 30% by weight), respectively. The tension test and compression test demonstrated that RP and CR incorporation has a positive effect on the deformability of ECC, especially on the tensile strain capacity.

A closed-loop life cycle assessment of recycled aggregate concrete utilization in China.

This paper studies the potential environmental impact of recycled coarse aggregate (RCA) for concrete production in China. According to the cradle-to-cradle theory, a closed-loop life cycle assessment (LCA) on recycled aggregate concrete (RAC) utilization in China with entire local life cycle inventory (LCI) is performed, regarding the environmental influence of cement content, aggregate production, transportation and waste landfilling. Special attention is paid on the primary resource and energy conservation, as well as climate protection induced by RAC applications.

Reclamation chain of waste concrete: A case study of Shanghai.

A mass of construction and demolition (C&D) waste are generated in Shanghai every year, and it has become a serious environment problem. Reclaiming the waste concrete to produce recycled aggregate (RA) and recycled aggregate concrete (RAC) is an effective method to reduce the C&D waste. This paper develops a reclamation chain of waste concrete based on the researches and practices in Shanghai.

Effect of Stress Amplitude on the Damping of Recycled Aggregate Concrete.

Damping characterizes the energy dissipation capacity of materials and structures, and it is affected by several external factors such as vibrating frequency, stress history, temperature, and stress amplitude. This study investigates the relationship between the damping and the stress amplitude of environment-friendly recycled aggregate concrete (RAC). First, a function model of a member's loss factor and stress amplitude was derived based on Lazan's damping-stress function.

Estimation of building-related construction and demolition waste in Shanghai.

One methodology is proposed to estimate the quantification and composition of building-related construction and demolition (C&D) waste in a fast developing region like Shanghai, PR China. The varieties of structure types and building waste intensities due to the requirement of progressive building design and structure codes in different decades are considered in this regional C&D waste estimation study. It is concluded that approximately 13.