Abstract
High-pressure forming is increasingly recognized as a promising method for producing low-energy masonry units from natural minerals and secondary raw materials. This review consolidates current knowledge on compressed earth blocks, cementitious high-pressure bricks, alkali-activated products, and ultra-high-pressure waste-derived bricks. Emphasis is placed on raw material selection, mixture preparation, forming moisture, compaction pressure, curing conditions, structure formation mechanisms, and resulting engineering properties. The literature indicates that pressure-induced particle rearrangement and pore reduction must be integrated with hydration, pozzolanic reactions, alkali activation, or carbonation to achieve stable long-term performance. Increasing pressure typically enhances density, strength, and water resistance up to an effective densification threshold, beyond which further pressure may yield limited benefits or induce microcracking and elastic recovery. Industrial, mining, construction, and agricultural wastes can substitute for significant proportions of natural raw materials; however, their use necessitates careful control of particle grading, chemical variability, soluble salts, and potentially hazardous components. The environmental advantages of avoiding firing may be offset by high Portland cement content, extended transport distances, and energy-intensive waste pretreatment. This review highlights insufficient standardization of terminology, specimen geometry, compaction procedures, curing regimes, and durability assessment as major obstacles to comparison. Future research should focus on long-term exposure testing, full-scale production, environmental safety, life-cycle assessment, and the development of low-carbon binder systems.