新型岩石基矿物掺合料体系的理论基础与工程应用研究

With the scale of state construction,cement consumption has reached 2.06 billion tons,of which rock and sand resources exploitation quantity is 10 billion tons,the amount of limestone powder inevitably emission during process of aggregate preparation is up to one billion tons,leading to a great environmental pollution.And mineral admixture such as fly ash and blast furnace slag with the total annual output is about 500 million tons,which used in the prsent engineering system is becoming a scarce resource,and resulting in an increase cost of transport and engineering.Environmental protection, energy conservation and waste utilisation and reducing engineering cost in a high-speed construction stage of the China is a problem waiting to be solved urgently.At the same time,if establishing the system of the replacment cement with rock base mineral admixture effectively by 10% to 20% by mass,which will save cement 200~400 million tons and have a significant impact on energy-saving and environmental protection.Therefore,the reseasch on ground limestone based mineral admixture taking limestone rock for intance will be carried out.Aiming at the existing scientific and technical bottleneck of this system,establishing its mechanism and influence law,constructing the model of ground limestone mineral admixture system hydration and hardening,proposing activity evaluation method,getting the engineering properties of cement concrete mixed with ground limestone and optimization and regulation of its engineering properties and producing good technical,economic and ecological benefits.

我国每年建设规模已达到水泥用量20.6亿吨，其中开采岩石和砂资源100亿吨，骨料制备过程中不可避免产生的石粉其每年的排放量高达10亿余吨，形成巨大的环境污染。而现有工程体系所用的矿物掺合料年产总量大约5亿吨的粉煤灰和矿粉已形成稀有资源，并导致运输和工程费用增加。保护环境、节能利废以及降低工程成本对处于高速建设期的中国是一个急待解决的重大课题。同时，若能建立岩石基矿物掺合料体系有效取代10％～20％的水泥将节约水泥资源2～4亿吨，这将对节能减排产生重大影响。因此，本课题将以石灰石岩石为例开展石灰石粉基矿物掺合料的系统研究，针对这一体系现存的科学问题和技术瓶颈，探明石灰石粉对水泥混凝土的作用机理及影响规律，构建石灰石粉基水泥混凝土体系水化硬化模型，提出石灰石粉活性评价方法，揭示石灰石粉基水泥混凝土的工程特性，从而调控、优化其工程性能，使其产生良好的技术、经济和生态效益。

混凝土所需骨料制备过程中产生了大量的石粉排放，将其作为混凝土的岩石基矿物掺合料不仅能减少环境污染，降低混凝土生产成本，还能缓解传统矿物掺合料供不应求的状况。本课题开展了以石灰石粉为重点的岩石基矿物掺合料系统研究，丰富了其对水泥基材料水化作用和微结构影响，完善了其对水泥混凝土的作用机理及影响规律，提出了其活性评价方法，揭示了掺石灰石粉水泥混凝土的工程特性，从而调控优化了其工程性能。.项目具体研究内容和成果包括：1）研究了CaCO3对水泥熟料单矿C3A和C3S的水化放热和水化产物的影响，得出了CaCO3对C3A和C3S水化存在的多种作用效应；研究了石灰石粉对水泥的水化作用及机理，得出了石灰石粉对水泥水化历程、水化产物、孔结构和界面结构的影响，丰富了石灰石粉矿物掺合料应用于水泥混凝土中的基础理论。2）研究了石灰石粉对水泥混凝土的流变特性、物理力学性能、体积稳定性和耐久性能的影响，得出了石灰石粉混凝土的工作性能、强度性能、抗收缩开裂性能、抗氯离子侵蚀性能和抗常温、低温硫酸盐侵蚀性能（抗TSA），得到了石灰石粉混凝土的工程特性。3）研究了多种组分对水泥-石灰石粉胶凝体系性能的优化研究，同时通过不同的组分复合，优化了其配合比，能制备出满足不同性能要求的石灰石粉混凝土。4）研究了石灰石粉在水泥基材料中的稀释效应、级配效应和异质成核效应，提出了科学的石灰石粉活性评价方法。.本项目通过石灰石粉混凝土的基础理论及其工程特性研究，为混凝土结构工程中安全、有效地使用石灰石粉提供了科学理论基础。