The Bond Properties Of Steel Fiber Reinforced ECC Material

ECC material due to its excellent mechanical properties, in engineering practice plays an increasingly important role in recent years, steel fiber reinforced ECC is gradually being recognized and widely used. To Bond properties of steel fiber reinforced material between-ECC, tests according to different strength classes and fiber content designed three groups with a total of more than 10, the use of round 12mm, ribbed 12mm, 16mm three kinds ribbed steel, production of molding 84 centers pullout specimens.Test on a universal testing machine, force sensors and displacement meter real-time monitoring and recording reinforced free end slip, slip loading end and the size of the drawing force, calculated by the formula to obtain complete conversion of each specimen bond-slip curve. Data obtained on the curve, analysis and comparison study the effect of cement-based strength, steel fiber volume content and other factors on the type of bar diameter on bond properties, the main conclusions are as follows:(1) Compressive strength of steel fiber-ECC material with increasing fiber content, but does not show a significant linear relationship between the addition of fiber material makes crack greatly enhanced;(2) Of reinforced steel fiber content free end-almost no influence of the loaded end slip curves, and the free end of the different cement-based intensity-loaded end slip curve there is a clear distinction, and the higher the strength of cement-based differences in the obviously, this is as a result of the reinforced cement anchoring force transmission section;(3) Steel fiber content is higher, drawing specimens ultimate bond strength and residual adhesive strength showed an increasing trend, but the ultimate bond strength of the effect is more pronounced; the intrinsic viscosity between the steel and the cement matrix knot strength will increase with the increase of cement-based strength, but substantially unaffected residual bond strength; bond properties of ribbed steel is much better than plain bars, ultimate bond strength greatly improved, but the sticky residue knot strength remains close to;(4) Data for the plain bar specimen results, based on statistics anchor eigenvalues regression, empirical formula is given the ultimate bond strength and residual bond strength; according to the specific circumstances of a simplified experimental model Xu Youling, and get round bar steel fiber-ECC bond slip relationship.