Because of the rapid growth of the Earth's population, the importance of the principle of sustainable development is increasing. In the context of civil engineering can be interpreted as the need for more rational use of materials with an emphasis on renewable resources. Timber-concrete composite (TCC), which can combine the better properties of timber and concrete in one composite material and reduce their disadvantages, is considered a promising composite for bending structures. Within the framework of the work, the impact of timber-to-concrete rigid connection defects on the behaviour of TCC slabs has been determined. A sustainable solution of TCC for bending structures with an innovative method of rigid connection production, which ensures the most effective synergy of the materials, was developed. The performance of the full composite action has been studied by numerical calculations and laboratory bending and shear tests. The tests showed a higher safety level of the proposed connection type than the adhesive connections formed by classical methods. A methodology and software for determining rational parameters and materials have been developed for two solutions of timber-concrete composite - with cross-laminated timber (CLT) panels and with plywood rib panels. The rationality criterion- cost factor- based on the cost of the materials per square meter of a slab is used. The reasonable limits for the use of TCC are determined by the developed software. CLT-concrete and plywood-concrete slabs have up to 44 % and 42 % lower cost factor values and 25 % and 33 % lower cross-section height at high vibration quality class compared to the most rational cross-sections of the same constructive solutions, but without a concrete layer. The comparison of the two constructive solutions discussed indicates that the cost factor for plywood-concrete composite slabs is lower than for CLT-concrete slabs, and a lower self-weight load also characterizes this solution. Experimental tests of both variants showed a smaller dispersion of results for timber-concrete composite specimens with plywood rib panels. The quality control of connection in the timber-concrete composite often is perceived as a limitation for using glued connections in practice. The possibilities of effective use of operational modal analysis - for global evaluation of the structure and ultrasonic testing - for local diagnostics of connections have been tested and determined. The proposed TCC solution involves abandoning traditional steel reinforcement in the concrete layer. The continuous steel reinforcement in the structure, especially in the current situation when the supply of this material to the Latvian market is complex, significantly increases the construction costs. Laboratory experiments have determined a positive effect of adding 0.5 % synthetic fibres to the behaviour of TCC slabs. Adding fibres results in better stress distribution and fragility reduction of the concrete layer. Thanks to the dispersed reinforcement, the integrity of the timber-concrete composite slabs is preserved in case of collapse. The doctoral thesis consists of general information, five chapters, conclusions, and a list of used literature. The thesis consists of 120 pages, 96 figures, 16 tables and 139 references and is written in Latvian.