Experimental Study On Compressive Stress-Strain Relationship Of Damage Concrete

:Concrete structure work in carbon dioxide, chemical medium erosion and freezing and thawing cycle for long periods. The mechanical properties and durability of concrete will deteriorate when concrete work in these environmental factors. Especially the bearing capacity of concrete structure will reduce under repeated loading, earthquake loading and fatigue loading, resulting in reducing the safety of concrete structure. In this regard, Study on compressive stress-strain curve relationship of damage concrete has great theoretical significance and practical engineering value to designing total life cycle of seismic and fatigue life of concrete structure. The main content of this paper are as follows:(1) Taking carbonated concrete of100mm×100mm×300mm as the reasearch object, which compressive strength are30Mpa. Firstly, Let these specimens were exposed to natural environment for twenty-eight days. Then, Put these specimens into carbonation of concrete box respectively for three days, seven days, fourteen days and twenty-eight days. After that, Measure carbonated concrete’s carbonation depth and put them under monotonic loading and repeated loading to measure its compressive stress-strain curve. Analysed carbonated concrete s characteristic values of compressive stress-strain curve which under repeated loading. At last, This article summarized the expression of compressive stress-strain curve for different carbonation depth.(2) Taking corroded concrete of100mm×100mm×300mm as the reasearch object, which compressive strength are30Mpa. Firstly, Let these specimens were exposed to natural environment for twenty-eight days. Then, Corrode these specimens with1%hydrochloric acid respectively for six days, twelve days, eighteen days, twenty-four days and thirty days. Put these corroded concrete under monotonic loading and repeated loading to measure its compressive stress-strain curve. Analysed corroded concrete’s characteristic values of compressive stress-strain curve which under repeated loading. At last, This article summarized the expression of compressive stress-strain curve for different corrosion time. (3) Taking frost-resistant concrete of100mm×100mm×400mm as the reasearch object, which compressive strength are30Mpa. Firstly, Put these specimens into Rapid freezing and thawing test machine for concrete were subjected to zero, twenty-five, fifty, seventy-five and one hundred freeze-thaw cycles. Quality loss and Dynamic modulus were measured by designed cycles. Secondly, Built the relational expression of Dynamic modulus and Freeze-thaw cycles, Quality loss and Freeze-thaw cycles. Put these frost-resistant concrete under monotonic loading and repeated loading to measure its compressive stress-strain curve. Analysed frost-resistant concrete’s characteristic values of compressive stress-strain curve which under repeated loading. At last, This article summarized the expression of compressive stress-strain curve for different Freeze-thaw cycles.