EXPERIMENTAL STUDY OF TEMPERATURE AGING INFLUENCE ON THE RESILIENCE OF MODIFIED BITUMINOUS CONCRETE FEATURING LIMESTONE CHIPPING RESIDUES
The paper provides the results of experimental study of elasticity modulus values of bituminous concrete featuring limestone fragments and vat residues in the process of aniline manufacture after the mixtures are heated to (+150 °С) for 1…7 hours. For our study we examined bituminous concrete with the following composition (by weight): solid particle crushed stone 5-10 mm or 5-20 mm - 47 %; screenings of rag stone - 43 %; limestone chipping residues M from 400 - 10 %; 90/130 bitumen - 5,0 % (over 100 %) and a vat residues from aniline production - 0,0…1,0 % (from the mass of bitumen). The paper analyses the process of value change in elasticity modulus and strength limits of concrete bitumen samples featuring limestone fragments under pressure and at +20°С and +50 °С, under water saturation of wet strength coefficient at high temperature. The mixtures are prepared in compliance with GOST 9128-2013 standard; the samples are produced using the standard procedure under contraction pressure of 40 MPa for 3 minute time period. Elasticity modulus was defined in laboratory conditions using a slightly modified method as compared with the standard procedures for UNIFRAME machine equipped with a memory unit, which enables automatic setting and storing the values of loading rate, existing loads and deformations. Other parameters were tested using standard procedures. It has been revealed that introducing vat residues into Bituminous concrete in aniline production results in a certain increase in water saturation, wet strength, elastic rigidity and crack strength coefficients of Bituminous concrete under decreased temperatures at the beginning of exploitation period, i.e. both - before the mixture is heated at high temperature and after a definite exploitation period. In authors' opinion the research results may be useful for undergraduate and postgraduate students dealing with the issues of long-term performance of highways and forest roads.