Geopolymers are inorganic polymers that form via the polycondensation reaction between an aluminum-silicate source and alkali or acidic activation. As is well known, the preparation process of ordinary Portland cement produces too much CO2, which is one of the main greenhouse gases. Geopolymers have a non-crystalline, amorphous network structure which gives them superior properties. Geopolymer types of cement are alternatives to the ordinary Portland cement (OPC) with some advantages and superior properties, such as better performance in durability, no CO2 emissions during production, anti-corrosive properties, acid resistance, heat and fire resistance, and sulfate and chloride attack resistance.

The problem that geopolymers and their corresponding mortars and concretes have is that self-shrinkage or cracks form inside their structure during the curing time or later. One of the solutions for this problem is reinforcing geopolymer-based mortars or concretes with different types of reinforcement materials.

The primary aim of this Special Issue is to collate original research and review articles including both fundamental and practical aspects, with a focus on the research area of reinforced geopolymer mortars and concretes. Submissions including real-life applications of reinforced geopolymer mortars or concretes are of particular interest.

Potential topics include but are not limited to the following:

• Recycled plastics, reinforced geopolymer mortars, and concretes
• Graphene reinforced geopolymer composites
• Molecular dynamics simulations of geopolymers, geopolymer composites, and mortars
• Flammability of geopolymer mortars and concretes
• Bamboo fiber reinforced geopolymers, geopolymer-based mortars, and concretes
• Chitin or chitosan fibers reinforced geopolymers, geopolymer-based mortars, and concretes
• Preparation and application of antibacterial geopolymers, geopolymer-based mortars, and concretes
• Carbon nanotube (CNT) reinforced geopolymers, geopolymer-based mortars, and concretes
• Steel fibers reinforced geopolymer-based mortars and concretes
• Glass fiber-reinforced geopolymers, geopolymer-based mortars, and concretes
• Synthetic organic polymer fibers reinforced geopolymers, geopolymer-based mortars, and concretes
• Cellulose, lignin, and hemicellulose fibers reinforced geopolymers, geopolymer-based mortars and concretes
• The use of geopolymers, geopolymer-based mortars, and concretes in radioactive/nuclear waste management