Sustainable cement-based concrete materials are primarily used for construction,among which vermiculite as lightweight fine aggregate gains more future development prospect.First,a bacterial solution was sprayed over ...Sustainable cement-based concrete materials are primarily used for construction,among which vermiculite as lightweight fine aggregate gains more future development prospect.First,a bacterial solution was sprayed over vermiculite and wrapped using calcium sulphoaluminate(CSA)cement to replace with fine aggregate in concrete.Secondly,based on a preliminary test on compressive strength results,10%of Ground Granulated Blast Furnace Slag(GGBS)and a healing solution proportion of 9:1 was selected for preparing self-healing concrete.The fine aggregate was replaced in concrete using vermiculite in 0%,5%,10%and 15%and the findings suggest that bacterial vermiculite replacement should be at most 5%to achieve better results in strength and durable properties.The strength enhancement observed for compressive strength,strength regain,split tensile strength,flexural strength,and ultrasonic pulse velocity were 29.22%,45.5%,34.02%,28.03%and 41.4%respectively.Surface crack healing at 7,14 and 28 days of BIVC was 38.23%,58.82%and 79.41%,which is 3–4%lower than internal crack healing.Microstructural analysis by Scanning Electron Microscopy(SEM),X-Ray Diffractometer(XRD),and Energy Dispersive Spectroscopy(EDS)reveals the existence of calcite,and it was formed due to the bio-mineral action of bacteria with available nutrients in sustainable concrete.展开更多
文摘Sustainable cement-based concrete materials are primarily used for construction,among which vermiculite as lightweight fine aggregate gains more future development prospect.First,a bacterial solution was sprayed over vermiculite and wrapped using calcium sulphoaluminate(CSA)cement to replace with fine aggregate in concrete.Secondly,based on a preliminary test on compressive strength results,10%of Ground Granulated Blast Furnace Slag(GGBS)and a healing solution proportion of 9:1 was selected for preparing self-healing concrete.The fine aggregate was replaced in concrete using vermiculite in 0%,5%,10%and 15%and the findings suggest that bacterial vermiculite replacement should be at most 5%to achieve better results in strength and durable properties.The strength enhancement observed for compressive strength,strength regain,split tensile strength,flexural strength,and ultrasonic pulse velocity were 29.22%,45.5%,34.02%,28.03%and 41.4%respectively.Surface crack healing at 7,14 and 28 days of BIVC was 38.23%,58.82%and 79.41%,which is 3–4%lower than internal crack healing.Microstructural analysis by Scanning Electron Microscopy(SEM),X-Ray Diffractometer(XRD),and Energy Dispersive Spectroscopy(EDS)reveals the existence of calcite,and it was formed due to the bio-mineral action of bacteria with available nutrients in sustainable concrete.
