In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of thi...In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of this study is therefore to investigate if the concrete produced with rationalized mix ratio can be adopted as conventional mix ratio in terms of minimum required compression strength of concrete for buildings. Specifically this work compared the conventional mix ratio of 350 kg of cement: 400 liters of sand: 800 liters of gravel for a cubic meter and the rationalized batch of 350 kg of cement: 600 liters of sand: 600 liters of 5/15 gravel, 15/25 gravel and a combination of 5/15 + 15/25 gravel. Average compressive tests’results for both the conventional and the rationalized mix ratios were found to meet the minimum compressive strength of 65% at 7 days, 90% at 14 days and 99% at 28 days for gravel size combination 5/15 + 15/25. Single size gravel of 5/15 and 15/25 did not meet the minimum required compressive strength of 20 N/mm<sup>2</sup> for the rationalized mix ratio at 28 days curing based on the minimum compressive strength required, this study arrives at the conclusion that the equal volumes of sand and gravel mix ratio of 350 kg/m<sup>3</sup> of cement: 600 liters of sand: 600 liters of gravel mix ratio can be adopted as a conventional concrete mix ratio for gravel size 5/15 + 15/25.展开更多
Considering actual construction conditions of Binchuan-Heqing Highway,this paper provides the C50 mix ratio conforming to engineering requirements by strictly controlling the quality of raw materials,optimizing the de...Considering actual construction conditions of Binchuan-Heqing Highway,this paper provides the C50 mix ratio conforming to engineering requirements by strictly controlling the quality of raw materials,optimizing the design of mix ratio scientifically,preparing superior C50 concrete 0 with manufactured sand,and optimizing the concrete mix ratio based on the adjustment of fly ash replacement,water-cement ratio,polycarboxylate-type water reducer mixing amount,sand ratio,etc.The result indicates that,the water-cement ratio has a great influence on the concrete strength,and if the ratio of coal ash is high in the binding material,the early compressive strength of the concrete will increase slowly.展开更多
文摘In recent years, the rationalization of concrete mix ratios which batches equal volumes of sand and gravel in building projects has been gaining grounds in the Cameroon construction industry. The main objective of this study is therefore to investigate if the concrete produced with rationalized mix ratio can be adopted as conventional mix ratio in terms of minimum required compression strength of concrete for buildings. Specifically this work compared the conventional mix ratio of 350 kg of cement: 400 liters of sand: 800 liters of gravel for a cubic meter and the rationalized batch of 350 kg of cement: 600 liters of sand: 600 liters of 5/15 gravel, 15/25 gravel and a combination of 5/15 + 15/25 gravel. Average compressive tests’results for both the conventional and the rationalized mix ratios were found to meet the minimum compressive strength of 65% at 7 days, 90% at 14 days and 99% at 28 days for gravel size combination 5/15 + 15/25. Single size gravel of 5/15 and 15/25 did not meet the minimum required compressive strength of 20 N/mm<sup>2</sup> for the rationalized mix ratio at 28 days curing based on the minimum compressive strength required, this study arrives at the conclusion that the equal volumes of sand and gravel mix ratio of 350 kg/m<sup>3</sup> of cement: 600 liters of sand: 600 liters of gravel mix ratio can be adopted as a conventional concrete mix ratio for gravel size 5/15 + 15/25.
文摘Considering actual construction conditions of Binchuan-Heqing Highway,this paper provides the C50 mix ratio conforming to engineering requirements by strictly controlling the quality of raw materials,optimizing the design of mix ratio scientifically,preparing superior C50 concrete 0 with manufactured sand,and optimizing the concrete mix ratio based on the adjustment of fly ash replacement,water-cement ratio,polycarboxylate-type water reducer mixing amount,sand ratio,etc.The result indicates that,the water-cement ratio has a great influence on the concrete strength,and if the ratio of coal ash is high in the binding material,the early compressive strength of the concrete will increase slowly.
