The application of polymer latex provides an additional approach when optimizing the properties of high–performance cement–based materials. Given that cement–based materials are extraordinarily sensitive to the characteristics and relative content of polymer latexes, identifying their influence is essential for application. This paper investigates the impact of polymer latex types and its relative content on the mechanical properties, hydration product, pore structure, and drying shrinkage of cement–based materials with a low water to binder ratio. The results showed that the mechanical properties, pore structure, and drying shrinkage of the styrene butadiene latex modified samples were better than those of ethylene vinyl acetate latex and silicone acrylic latex modified ones. Incremental increases to the polymer to cement ratio induces a slight reduction on compressive strength, and styrene–butadiene latex promotes tensile strength. Polymer latex hinders the transformation from ettringite to monosulfate, reducing the bound water and portlandite generated. Increasing the polymer content induces more significant stretching in the vibration peak of SO₄ from ettringite. Further incorporation of polymer latex contributes to ettringite precipitation and the decline of harmful pores. Polymer addition also results in lower drying shrinkage compared with the reference group.

Three-dimensional concrete printing technology provides the possibility to fabricate specific and eco-friendly concrete components for application on shorelines or in other areas, providing environmental protection. In this study, solid wastes in Hong Kong are employed for low-pH 3D printing concrete to further decrease the impact on the environment. The results indicate that WGP replacement in a classic low-pH recipe leads to lower yield stress and surface pH, as well as volume stability. The employment of slag improves workability and printability, but maintains the surface pH and drying shrinkage. The printing height is not merely determined by slump flow, and contributions from every binder on the surface pH are quantified based on simplified calculations. Reducing OPC and increasing SF in the classic low-pH recipe achieves the best printing performance and improved environmental friendliness.