In accordance with the global needs of humanity, the construction requires the creation of energy-efficient, environmentally friendly and durable buildings and infrastructure, which necessitates the use of sustainable building materials. The main directions of their development are the replacement of high-energy materials with a significant carbon footprint with more environmentally friendly materials and the use of waste to replace natural materials. The huge volumes of aggregate use have a significant impact on the environment, which must be taken into account when designing environmentally friendly concrete. The paper presents researches of the properties of cement systems using wet fly ash as a partial replacement for Portland cement, as well as rubber aggregates as a replacement of sand. Mixtures were produced in which rubber crumb partially replaced fine aggregate with 1.0%, 2.0%, 5.0% and 10% of the weight. It was shown that the compressive strength of systems decreased with increasing crumb rubber content. The 28-day flexural strength for 10% rubber replacement decreased by 22.7%. The addition of rubber increases the crack resistance of composites. The crack resistance coefficient of cement based composite with rubber crumb and ash, increases by 22.8% compared to the control composite.