With the development of global industry and human living standards, the consumption of non-renewable resources and energy is growing rapidly, posing a serious threat to the sustainability of our natural environment. Portland cement (PC) is the most widely utilized binder in concretes, mortars, grouts and pastes, yet its production process is energy-intensive and emits a substantial amount of greenhouse gases (in particular, CO2). Many efforts have been devoted to developing innovative solutions that can reduce the use of PC in cementitious materials. For instance, in the last three decades numerous studies have focused on the replacement of PC in environmentally friendly concrete with solid waste or industrial byproducts (e.g. steel slags, fly ashes, desulfurized gypsum, coal gangue and tailings, and mining wastes). Recent years have seen increased focus on the upcycling (vs. recycling) of such waste or byproducts in “green” cementitious materials, by achieving satisfactory and balanced performances in mechanical strengths, durability, and other functions.

It is also noteworthy that the energy consumption of buildings accounts for approximately 30–40% of the total global energy consumption. Cementitious concrete is the most widely used building material; as such, its considerable energy footprint calls for innovations in design, materials and manufacturing to enable improved energy efficiency. Of the current energy-saving approaches, the use of phase change materials (PCMs) is recognized as one of the most promising. PCMs endow the cementitious materials with significant thermal energy storage capacity and thus make them desirable for building energy efficiency. While various PCMs have been incorporated into cementitious materials, there are still challenges in terms of the packaging technology of PCMs, manufacturing method of thermal energy storage cementitious material, characterization techniques, numerical simulation, long-term performance, and life-cycle assessment.

The aim of this Special Issue is to publish original research and review articles that present the recent advances in eco-friendly and energy-saving cementitious materials, of which the life-cycle sustainability is improved by replacing cement with solid waste or industrial byproducts, by incorporating PCMs, or both.

Potential topics include but are not limited to the following:

• High-performance and high value-added solid waste utilization
• Beneficial use or recycling of solid waste and byproducts in cementitious materials
• Thermal energy capacity and heat-transfer characteristics
• Advanced manufacturing: materials, processes, and techniques
• Design and manufacturing of form-stable PCMs
• Cementitious materials incorporating PCMs
• Numerical simulation of energy-saving cementitious materials
• Assessment of mechanical properties, durability and sustainability
• Test methods and characterization techniques
• Structural performance and modelling
• Economic evaluation and service life prediction