RESEARCH
INGENIEUR
Coal Waste in Concrete Production
By Zuhairi Abd . Hamid , Construction Industry Development Board
Nor Hasanah Abdul Shukor Lim , Mahmood Md . Tahir , Tan Shea Qin , Hossein Mohammadhoseini , Construction Research Centre ( UTM CRC ), Universiti Teknologi Malaysia
Nur Farhayu Ariffin , Faculty of Civil Engineering and Earth Resources , Universiti Malaysia Pahang
The rapid growth of the construction industry has increased the consumption of raw materials and as such it is depleting natural resources . Therefore , the need for abundant and cheap materials is getting more attention . Coal waste is abundantly available from coal generating power plants and could be available as a construction material . The aim of this research was to investigate the performance of concrete incorporating a high volume of coal waste as cement and an aggregate replacement . The specimens that were used were prepared by using 30 % coal fly ash as cement replacement and coal bottom ash as full replacement of the aggregates . The specimens were cast using 100mm x 100mm x 100mm cubes . There were several tests conducted in the study which focused on the characteristics of the materials in fresh and hardened properties of concrete . It was found that the workability and density of concrete decreases with the inclusion of coal waste . Overall , it was found that coal waste could be used as an aggregate replacement in concrete and furthermore it enhanced the mechanical properties of plain concrete .
The population of Malaysia is expected to grow
to about 32 million by 2020 . This implies that the population will increase by approximately 1.02 % within a period of two years [ 1 ]. The nation ’ s economy relies mainly on the construction industry which is the leading sector in terms of contribution to the economic development of the country . A lot of construction activities are taking place because the country is among the developing nations in the world . The construction activities are creating a high demand for concrete resulting in a huge exploitation of natural aggregate resources [ 2 ]. In addition , owing to its desirable physical and mechanical properties , concrete is the most preferred building material in the construction sector . Every year , at least ten billion tonnes of concrete is manufactured . This is expected to increase to about 18 billion tonnes within the next three decades due to the demand for housing which is expected to be high if the current high population growth rate continues [ 3 ]. These disturbing projections call for the need to find alternative construction materials in order to minimise excessive exploitation of natural resources . As aggregate is the main material used in concrete mixes , an alternative material that is more affordable and sustainable is the best way to minimise the depletion of this natural resources as well as reducing the overall cost of construction . Recently , various construction
56 VOL 83 JULY-SEPTEMBER 2020