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High performance lightweight concrete (HPLC) characterized by low density, high strength and good durability, has prosperous application prospects in civil engineering. In this experiment, the modified Andreasen and Andersen model was used to design the initial mixture of HPLC. Shale ceramic sand (SCS) with different content was used to replace lightweight internal curing sand to prepare HPLC. The effect of different content of SCS on workability, mechanical properties and durability of HPLC were systematically investigated. In addition, this work explored the effect of SCS on the micro-morphology and pore structure of HPLC. It is found that: 1) When the replacement rate of SCS is 100%, the apparent density of HPLC is 1 848. 3 kg/m³, and its compressive strength is 123. 22 MPa. 2) The addition of SCS can improve the mechanical properties of HPLC, and the compressive strength, flexural strength and elastic modulus of HPLC increase by 8. 88% ~ 47. 92%, 22. 50% ~ 56. 30% and 3. 49% ~ 14. 03%, respectively. 3) SCS can improve the durability of HPLC. When SCS replacement rate is 100%, the chloride migration coefficient of HPLC is reduced by 32. 52%, compared to the control group. 4) Due to the addition of SCS, the microstructure of HPLC is significantly improved, and the porosity of HPLC reduces by 14. 86% ~28. 24%. [ABSTRACT FROM AUTHOR]

Within the domain of municipal solid waste (MSW) management, incineration is recognized as an efficient volume reduction method, yet it produces substantial quantities of bottom ash (IBA). Redirecting IBA into cementitious frameworks is challenging due to diminished workability, mechanical properties, and durability. This study investigates alumina micro powder (ALMP)'s effect on improving the mechanical and durability aspects of ecological ultra-high performance concrete (EUHPC) produced with IBA. The research examines ALMP's role at various doping levels on the EUHPC's rheological properties, mechanical strengths, durability indices, ultrasonic pulse velocity (UPV), and elastic modulus. Additionally, nanoindentation tests discern ALMP's reinforcing effect on EUHPC's stiffness. Summarizing key findings: ALMP significantly enhances EUHPC's flexural and compressive strengths, with increases ranging from 6.98 % to 24.87 % and 12.39–20.81 %, respectively. Moreover, ALMP raises the elastic modulus by 6.05–19.07% and UPV by 3.11–7.18 %, reflecting a denser, more compact matrix structure. Durability enhancements are evidenced by reductions in drying shrinkage by 4.41–20.01 % and decreased chloride migration by 7.01–22.14 %. Nanoindentation reveals a densification in the microstructure, with escalated high-density C-S-H phases and reduced low-density C-S-H and unhydrated materials. IBA replacement yields energy savings of 11.43 %, CO 2 emission reduction of 7.01 %, and cost savings of 1.18 %. The optimal ALMP inclusion is identified at 10 %, balancing workability, mechanical and microstructural benefits in EUHPC. These revelations position IBA as a useful component in the concrete sector and advocate for ALMP as a beneficial adjunct to elevate the performance of IBA-based concrete towards sustainable development goals. • Mixture of eco-UHPC was designed via MAA particle packing model. • Properties of eco-UHPC were improved via Al 2 O 3 micro-powder. • Optimal content of Al 2 O 3 micro-powder in eco-UHPC was 10%. • Al 2 O 3 micro-powder contributed to a denser microstructure of eco-UHPC. • Environmental friendliness of eco-UHPC was improved via Al 2 O 3 micro-powder. [ABSTRACT FROM AUTHOR]