The use of seawater sea-sand concrete in marine infrastructure not only offers significant sustainability benefits by minimizing the energy consumption and carbon emissions associated with transportation activities, but also helps mitigate the environmental impact caused by excessive sand mining in riverbeds. The study presented in this paper aims to contribute to this growing area of research by introducing self-strain sensing capability to ultra-high-performance seawater sea-sand concrete (UHPSSC) through the incorporation of cost-effective nanocarbon black (nCB) as a functional filler. Mix designs with different nCB contents were formulated and tested for compressive strength, microstructure and piezoresistive behaviour under different curing conditions. The study concludes that, although the addition of nCB generally decreases the workability and compressive strength of UHPSSC, nCB-UHPSSC with reasonably good properties (i.e., slump spread >160 mm, compressive strength >140 MPa) can be successfully achieved, and its compressive strength can be further increased by one-day dry curing at 105 °C ± 1 °C after 28-day water immersion. The study also shows that the developed nCB-UHPSSC possesses stable and repeatable piezoresistive response with a high gauge factor up to over 160. With its outstanding mechanical and piezoresistive properties, the newly developed nCB-UHPSSC is an economically viable and environmentally friendly option for the construction and monitoring of marine and coastal structures.

中文翻译：

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纳米炭黑基超高性能海水海砂混凝土 （UHPSSC），具有自应变传感能力


在海洋基础设施中使用海水海砂混凝土不仅通过最大限度地减少与运输活动相关的能源消耗和碳排放，提供了显着的可持续性优势，还有助于减轻河床过度采砂对环境的影响。本文提出的研究旨在通过加入具有成本效益的纳米碳黑 （nCB） 作为功能性填料，将自应变感应功能引入超高性能海水海砂混凝土 （UHPSSC），从而为这一不断增长的研究领域做出贡献。配制具有不同 nCB 含量的混合物设计，并测试了不同固化条件下的抗压强度、微观结构和压阻行为。研究得出的结论是，虽然 nCB 的添加通常会降低 UHPSSC 的加工性能和抗压强度，但可以成功实现具有相当好性能（即坍落度扩展> 160 mm，抗压强度> 140 MPa）的 nCB-UHPSSC，并且在水中浸泡 28 天后，在 105°C ± 1°C 下干固化 1 天可以进一步提高其抗压强度。该研究还表明，开发的 nCB-UHPSSC 具有稳定且可重复的压阻响应，应变片系数高达 160 以上。凭借其出色的机械和压阻性能，新开发的 nCB-UHPSSC 是海洋和沿海结构建造和监测的经济可行且环保的选择。