The microstructural development of mortar bars with silica glass aggregate undergoing alkali-silica reaction (ASR) under the conditions of American Society for Testing and Materials (ASTM) Standard Test C1260 was analyzed using scanning electron microscopy and qualitative X-ray microanalysis. Cracking in the aggregate, the hydrated paste, and the paste-aggregate interface was important in the development of the microstructure. Cracks were characterized according to their location, their relationship to other cracks, and whether they are filled with ASR gel. Expansion of the bars was approximately 1% at 12 days and 2% at 53 days. They fell apart by 63 days. The bars contained two zones, an inner region that was undergoing ASR and an outer and much more highly damaged zone that extended further inward over time. Evidence of ASR was present even during the period when specimens were immersed in water, prior to immersion in NaOH solution.

Exposure of concrete structures to chloride-bearing solutions such as sea water or de-icing salts brine can affect their durability to stand against deterioration caused by corrosion of steel reinforcement. In order to monitor the chloride ingress into concrete, embedded chloride sensors can be used in concrete structures. Through the sensors, they monitor the initiation of corrosion of steel reinforcement with time, and measure the open circuit potential and polarisation of steel reinforcement, humidity inside the concrete, chloride content and many more. This paper provides an overview of the latest development of chloride permeation measurement in concrete by evaluating the current techniques being used in industry and highlighting a new approach to monitor chloride ion progress in concrete structures wirelessly.

Water treatment sludge (WTS), hydrothermally synthesized powder (HSP) using the WTS, and CuO added HSP (CuHSP) after heat treatment at 500℃ were prepared and its hydrogen sulfide (H₂S) removal properties were investigated. The physicochemical properties of adsorbents were studied by N₂ adsorption-desorption, scanning electron microscope, x-ray diffraction, and thermogravimetric-differential thermal analysis. The specific surface area for the WTS was 42.7㎡/g and was increased by 78.1㎡/g after the hydrothermal reaction and was maximized by 168.7㎡/g after the heat treatment at 500℃ for 1 h. The breakthrough time of the WTS, HSP, and CuHSP for H₂S removal at 25℃ was measured for 10 min, 20 min, and 170 min, respectively, thus demonstrating an effective application of WTS as the catalytic carrier for low temperature H₂S removal.