疏水改性煅烧硅藻土砂浆的制备及性能OA

To enhance the waterproofing and impermeability of cement-based materials,this paper proposed a method for preparing green superhydrophobic powder.Using stearic acid as modifier,calcined diatomite(CD)underwent hydrophobic modification via mechanical ball milling.Process parameters were optimized with contact angle as the primary evaluation metric,successfully yielding modified calcined diatomite(SA-CD)with outstanding hydrophobic properties.The SA-CD was characterized using X-ray diffractometer(XRD),Fourier transform infrared spectrophotometer(FTIR),and scanning electron microscopy(SEM).The effects of substituting cement with SA-CD at different dosages on mortar properties were systematically investigated.Results indicate that under process conditions of 3％(mass fraction)stearic acid dosage,30 min ball milling time,and 500 r/min rotation speed,the prepared SA-CD shows a contact angle of 152°.As the SA-CD dosage increases,the mortar contact angle continuously rises while the capillary water absorption coefficient significantly decreases,simultaneously exhibiting a flow trend that initially increases before decreasing.At a 6％(mass fraction)SA-CD,the mortar's 28 d flexural strength and compressive strength improve by 8.81％and 10.44％,respectively.Microscopic analysis indicates that moderate SA-CD dosage improves pore structure and enhances density,thereby strengthening the mortar's overall performance.