疏浚砂细粒混凝土性能及含泥量影响研究

Research on the performance and mud content of fine grained concrete with dredged sand

为使航道疏浚砂制备新型无粗骨料细粒混凝土替代普通混凝土,对比分析了石灰石粉和粉煤灰填料细粒混凝土流动性、抗压强度、抗冲磨强度等物理力学及耐久性能,探讨了疏浚砂不同含泥量(1.3%、5.3%、9.3%、13.3%)对细粒混凝土性能影响。结果表明粉煤灰和石灰石粉为填料的干混物料最大堆积密度分别达2 083.8 kg/m^(3)和1 979.9kg/m^(3),最大堆积密度下填料与砂子的质量比分别为0.13和0.10,28 d抗压强度分别达39.8 MPa和34.1 MPa;较之1.3%含泥量,以粉煤灰为填料含泥量为13.3%的细粒混凝土3 d、28 d和90 d抗压强度分别降低了27.8%、13.5%和16.4%。含泥量少的试样表观密度更高、泌水性降低,保水性和工作性更好。制备的细粒混凝土可以替代普通混凝土制备路面砖、联锁块、鱼槽砖、扭王块等小型预制块体,就近应用于航道整治、道路或市政工程。

In order to prepare a new type of fine-grained concrete without coarse aggregate instead of ordinary concrete using dredged sand in channels,the physical and mechanical properties,such as mobility,compressive strength and abrasion resistance of fine-grained concrete filled with limestone powder and fly ash were compared and analyzed,and the influence of different mud contents(1.3%,5.3%,9.3%,13.3%)of dredged sand on the performance of fine-grained concrete was explored.The results showed that the maximum bulk densities of dry mixed materials filled with fly ash and limestone powder were 2083.8 kg/m^(3) and 1979.9 kg/m^(3),respectively.The ratio of filler to sand was 0.13 and 0.10,and the compressive strength at 28 days was 39.8 MPa and 34.1 MPa,respectively;Compared to the 1.3%mud content,the compressive strength of fine-grained concrete with a mud content of 13.3%filled with fly ash at 3 days,28 days,and 90 days decreased by 27.8%,13.5%,and 16.4%,respectively.Samples with lower mud content have higher apparent density,lower bleeding capacity,and better water retention and workability.The prepared fine-grained concrete can replace ordinary concrete to prepare small prefabricated blocks such as pavement bricks,interlocking blocks,fish groove bricks,and twisted king blocks,which can be applied nearby in waterway regulation,roads,or municipal engineering.