June 17, 2020

New Geo-material for Reclamation: Coal Ash-hardened Marine Soil

Extensive reclamations such as the Airport 3rd Runway System, Tung Chung New Town Extension and the Lantau Tomorrow Vision are proposed and these megaprojects require over 500 million tonnes of backfilling material. However, local fill banks only provide less than 10 million tonnes yearly. In order to alleviate the shortage, this study aims at producing a new geo-material by hardening soft marine soil primarily with coal ash generated from power plants.

Unconfined compression tests were carried out on hardened soil specimens. A set of variables were tested to examine the optimum mix design. About half of the specimens achieved an unconfined compressive strength of over 1 MPa.

The result shows that water to stabiliser ratio and the curing duration are the key strength-contributing factors. It was also found that the unconfined compressive strength of hardened soil is nearly proportional to its deformation moduli. These showed that coal ash is effective yet economic for hardening marine soil.

MEASURE: A SenseHat Smart Home Measuring System

This project fully utilises the sensors on SenseHat to build a SenseHat smart home measuring System MEASURE. There are three functionalities provided by MEASURE: Level meter, Compass, and HomeKit Integration. Level meter can detect if a line is horizontal or if a surface is flat, and a compass can calculate the degrees turned as well as finding correct directions. If not in use, MEASURE can be a perfect HomeKit accessory that reports readings to your device. So MEASURE is a smart tool that can detect temperature and humidity right at your mobile and help determine positions for furniture placement. It can also provide angle guidance for homemade DIY stuff, and assist you in many other areas.