INVESTIGATION OF THE CREEP EFFECT ON THE STRESS-STRAIN STATE ON TIMBER-REINFORCED CONCRETE MULTISTOREY BUILDINGS

Abstract

In the conditions of military aggression against Ukraine, a special attention should 
be payed to the development of innovative solutions in various fields, which will allow effective 
rehabilitation of veterans and civilians. The building as an artificial environment is an integral part of 
how a person experiences trauma and has the potential to calm the body's response to perceived 
stressors by modulating and leveling the surrounding triggers. The development of project based on 
the concept of biopositive design involves taking into account the criteria of biophilic design, the use 
of "green" environmentally safe materials and resource-efficient structural solutions. 
The  article  presents  the  results  of  the  experimental  design  of  a  biopositive  rehabilitation 
building using the example of a prototype project of a residential block. The proposed structural 
solution of a biopositive building-prototype consisting of modular prefabricated elements: three-layer 
panels for walls and roof, consisting of two layers of cross-glued wood, connected with each other 
by flexible ties, and heat and sound insulation arranged between the layers made of an effective 
environmentally friendly material; ribbed floor panels consisting of glulam beams and cross-glued 
wood slabs, joined together with high-strength bio-based non-formaldehyde glue. 
To substantiate the proposed structural solution of the biopositive building, a study of the stress-
strain state was carried  out using the  LIRA-CAD software complex. Theoretical provisions were 
formulated and an assessment of the degree of utilization of the load-bearing capacity of structural 
elements made of cross-laminated and glued laminated timber as well as an analysis of deflections 
and displacements was carried out. The degree of utilization of the load-bearing capacity of the floor 
panel in terms of normal stresses from the action of the bending moment is 45%, in terms of shear 
stresses is 18%. For wall and roof panels under the simultaneous action of compressive and bending 
stresses, the degree of utilization of the load-bearing capacity is 58%. The calculated floor deflection 
considering creep deformations and the maximum horizontal displacements from the wind load do 
not exceed the maximum allowable values.