Flume investigation on bed load transport and bedforms in simple channels

Massive floods hit various states in Malaysia such as Pahang, Kelantan, Johor, Terengganu, Sabah and Sarawak. It caused widespread damages to properties, infrastructures, human suffering and even deaths. More frequent floods incidents and soil erosion are reported which lead to sedimentation problems in the drainage and river systems due to urbanisation. It is important to understand the sedimentation process and the behaviour of bed forms in the water course for post-flood events. However, it is risky and dangerous to conduct field study during occurrence of flooding. Laboratory study has been chosen as an alternative to fulfill the objectives. Experimental investigations on the bed load transport and bed forms in simple channels have been undertaken. Small and large flume models are used in the laboratory. The effects of flow on mobile sandy bed channel and bed load transportation are studied by using a modified flume with an asymmetric straight compound channel. However, the findings on rate of transport and bed formation for non-flooding cases are presented in this paper. It is found that the bed formation profiles for both channels are different due to scale and flume characteristics. The bed forms, erosion and deposition processes are significantly influenced by the water velocity in the channel. The bed forms observed for large flume are repeating ripples and dunes; meanwhile variable of ripples are observed in small flume

The effects of seaweed powder to the properties of polymer modified concrete

Eucheuma Cottonii is a sea plant that commonly known as seaweed grows abundantly and part of the products in agricultural industries. The effects of alginate from seaweed benefited the properties of composites due to its advantage as a hydrophilic gelling material. This paper investigates the effects of Eucheuma Cottonii in polymer modified concrete. The investigations covers on the physical properties and mechanical properties of the polymer modified concrete based on different percentages of seaweed powder. The percentages chosen are 10%, 20%, 30%, 40% and 50% cement replacement inside polymer modified concrete. The effects on the seaweed powder percentage to the properties of polymer modified concrete are determined through microstructural, water absorption, pulse velocity, compressive strength and indirect tensile strength. Findings from the experimental works show that an optimum seaweed powder percentage into polymer modified concrete is 20% with improvement shows from the mechanical properties. It can be concluded that, seaweed powder potentially acted as a binder in polymer modified concrete and suitably chosen as a sustainable material inside polymer modified concrete

Building condition ratings using infrared thermography: a preliminary study

Deterioration and defects in building components are key aspects to consider when assessing buildings’ conditions, as they may influence the building’s functionality. The typical defects include cracking, moisture, dampness, and architectural defects. This paper aims to evaluate the defects in a building using a non-destructive testing (NDT), which is the Infrared Thermography (IRT) method. A visual inspection method is then conducted to verify the results of the IRT method. The combination of IRT and visual inspection methods can identify the type of defect and level of severity more accurately. In both methods, ratings or scores are given to the collected defect data to determine the consistency between them. Two (2) buildings were selected as case studies; AA1 and BB2 are multistorey buildings. From those, 51 and 67 spots were taken from the IRT method and further verification process, respectively. Among the defects that were found were moisture, dampness, cracking, staining, chipping, and flaking paint. From all the findings, IRT was found to be comparable with the visual inspection results for serious defects such as cracking and flaking paint. However, IRT was believed to underestimate the architectural defects of staining and chipping. Even so, serious defects such as dampness were also underestimated in IRT due to the fact that the temperature difference between different ratings will not differ much. In conclusion, the IRT method has the potential to be used as a tool for building condition rating. However, it should be assisted with a visual inspection, and more research needs to be conducted for its practicality