Ngoc Kien Bui

Recently, decreasing natural sources of aggregate accompanied by increasing large quantitiesof construction and demolition waste (CDW) cause challenges for environment and construction industry. Asignificant solution for this is to recycle CDW as a new aggregate source for concrete. However, usingrecycled concrete aggregate (RCA) in concrete involves various obstacles and controversial issues incontrolling the quality of recycled aggregate concrete (RAC). This study is an effort to improve the q

This study investigates the wet carbonation of concrete fines with CO2 and natural air gas bubbling in a carbonation system at low temperatures. After the air- and CO2-wet carbonations, the properties of a solution and hydrated cement paste powder are determined. In the air and CO2-wet carbonations, more Ca is extracted into the solution at a low temperature of 5°C. This high Ca concentration in the solution through air-wet carbonation primarily originates from the portlandite and unhydrated pha

The study investigates the effects of the particle size distribution (PSD) of aggregates on the properties of calcium carbonate concrete (CCC). Fifteen different types of aggregate PSDs were designed to select the appropriate PSD for CCC, based on the experimental data. Notably, the compressive strength of the CCC depends on the aggregate PSD, fineness modulus of the aggregates, packing ratio, and the amount of solution moving throughout the specimen. After one-day CCC processing, its compressiv

In sulphur–bitumen binder (SBB), sulphur enhanced rheological properties with low sulphur content and acting as filler with high sulphur content. The paper presents results of penetration, softening temperatures, rheological characteristics of SBB at different curing days at room temperature with different sulphur/bitumen ratios of 10/90; 20/80; 30/70; 40/60. Additionally, the rotational viscosity testing on SBB at three temperatures 120°C, 135°C, 150°C was conducted to determine the mixing and

The long-term microstructural evolution of hardened cement paste under nearly two years of enforced carbonation was examined using water vapor sorption and 1 H NMR relaxometry. The results show that nanopore evolution, including interlayer spaces and gel pores, in carbonation at different relative humidity (SDC) was reduced significantly by as much as approximately 50 % degree of carbonation (DoC). In contrast, wet carbonation (WC) showed distinct pore changes and rapid matrix degradation from s

A compacted concrete waste composite material (CWC) is developed using a cold compaction approach with recycled concrete waste particles, without the use of cement. This study aims to investigate the effects of carbonation and the original quality of the concrete waste (CW) particles on the properties of composite material, with the goal of proposing a pretreatment of concrete waste particles which proposed for CO2 sequestered for producing CWC with attained strength. This study found that the o

Abstract This study provides a comprehensive evaluation of the performance of hot mix asphalt concrete incorporating sulfur waste (HMAS) as a partial replacement for bitumen binders during extended curing times, aiming to investigate the evolution of strength in asphalt concrete containing sulfur after paving and determine the effect of sulfur waste on the mechanical properties and performance of HMAS at later ages. The optimal binder content in asphalt concrete containing sulfur waste was deter