http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/62 2026-04-21T22:00:21Z 2026-04-21T22:00:21Z HASAN, LT MD MONIRUL FERDOUS, LT S.A SHAH NEOWAZ KHAN, ABDUL HANNAN http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/638 2025-10-13T12:44:04Z 2018-12-01T00:00:00Z

COMPARATIVE STUDY BETWEEN NATURAL COARSE AGGREGATE (BRICK AND STONE) AND RECYCLED CONCRETE AGGREGATE (RCA) AND USE OF ADMIXTURE IN RCA FOR THE PURPOSE OF REGAINING THE INITIAL CONCRETE STRENGTH HASAN, LT MD MONIRUL; FERDOUS, LT S.A SHAH NEOWAZ; KHAN, ABDUL HANNAN In the present context of Bangladesh, it has been seen that most of the time after demolishing any concrete structure, demolished aggregates are hardly used or recycled for further construction work. This demolished aggregate has a reasonable amount of monetary value. But rather than being used for further construction work it turns into the garbage and pollutes our environment as well as become a burden for us. This happens due to most of the people have the idea that this recycled concrete hardly possesses any strength. Again, in Dhaka and major cities in our country, the requirement of the road has increased significantly inside the town area. Most of these roads are constructed demolishing the concrete structure and producing demolished concrete as well as increasing carrying cost of this demolished concrete. So in this thesis work it has been tried to show the relative comparison of natural coarse aggregate(NCA) and recycled concrete aggregate(RCA) as well as regaining strength by mixing admixture with recycled concrete aggregate(RCA) so that recycled concrete aggregate(RCA) can be potential substitute natural coarse aggregate(NCA). So that aggregate of demolished concrete structure can be recycled for further construction rather than dumping. This will in one hand reduce pollution as well as reduce the overall cost. .For the purpose of thesis work 1st class brick, 3rd class brick, and stone chips have been used. Using this natural course aggregate (NCA) cylinder block was cast with a simple ratio of 1:1.5:3. Then the compressive and tensile strength was checked after 28 days. Aggregate property tests like Aggregate crushing value(ACV),Aggregate impact value (AIV) , Elongation index(EI) , Flakiness index(FI), Los Angles abrasion test(LAAV),unit weight, specific gravity, Absorption capacity and void ratio test were done with both natural coarse aggregate(NCA) and recycled concrete aggregate(RCA) before casting of cylinder. This tests were done to draw a conclusion and compare between the natural coarse aggregate (NCA) and recycled concrete aggregate (RCA). For casting using ii Abstract recycled concrete aggregate (RCA) mix ratio of 1:1.5:3, water-cement ratio, brand and type of cement, sand, and grading of aggregate were kept same as casting using natural coarse aggregate (NCA). After recycling once admixture was mixed with recycled concrete aggregate (RCA) show how much strength can be regained. It is found that a significant amount of strength was regained and it is very compatible and close to the initial strength. Thus a cost comparison was also done using natural coarse aggregate (NCA) and recycled concrete aggregate (RCA) and found to be very fruitful to use recycled concrete aggregate (RCA). Finally using this dumped recycled concrete aggregate (RCA), developing country like Bangladesh can be benefited from the point of monetary value and environmental issue like saving the natural resource, reducing fuel consumption, low carbon emission, reuse of waste material and stepping one step forward in green building concept.

2018-12-01T00:00:00Z