Tensile creep of concrete at early ages is one of the important factors that affect the stress of restrained and partly restrained concrete. But only few data are available on tensile creep of concrete. The effect of ground slag on tensile creep was studied using lever-type tensile creep tester. Early age tensile basic creep of concrete loaded at the age of 3 days was researched. Results show t...

The compressive creep and recovery of foam earplugs was studied at various applied stresses leading to different fi nal creep strains. Deformation was determined from digital videos of the earplugs via image processing software. Creep could not be modeled by a single exponential in time; creep approximated a power law in time. Nonlinear viscoelasticity was observed: creep compliance depends on ...

All three burning plasma experiments discussed at Snowmass during the summer of 2002, use preloaded structures to resist some component of the operating loads. For the resistive pulsed reactors, it is the preloads which introduce the most noticeable creep responses because these loads are applied for much longer than the operating loads. If the preloads are maintained during shut-down and maint...

In order to characterize the creep behaviors of 2219 aluminum alloy at different temperatures and stress levels, a RWS-50 Electronic Creep Testing Machine (Zhuhai SUST Electrical Equipment Company, Zhuhai, China) was used for creep experiment at temperatures of 353~458 k and experimental stresses of 130~170 MPa. It was discovered that this alloy displayed classical creep curve characteristics i...

The effectiveness of silica sol grout on mudstones is reported in this paper. Using X-ray diffraction (XRD), the study investigates how the silica sol grout modifies mudstone mineralogy. Micropore sizes and mechanical properties of the mudstone before and after grouting with four different materials were determined with a surface area/porosity analyser and by uniaxial compression. Tests show th...

Fractional order theory was used to characterize the accelerated creep phase of a nonlinear model. To accurately describe each stage anthracite model, “gyroscope” unit introduced by combining Heaviside function and damage definition. The effect on determined designing completing three-axis graded-separation loading tests anthracite. test curves were combined classify into five stages: transient...

This paper is concerned with the creep-damage modelling of a Grade 91 pressurised header, which was observed to undergo in-service cracking in weldments. A multi-axial creep damage model Kachanov type, single state variable, has been implemented into finite element analysis study responses weldments and sub-zones i.e. base metal (BM), weld (WM) heat-affected zone (HAZ). Material properties for ...

Based on the latest laboratory test and prospect well data of G layer in south depression of D basin, the source rock、reservoir、cap-rock and preservation forming condition of tight oil and gas within research area is analyzed. The results indicate that the widely distributed dark mudstone of J layer has rather high organic content .IIb and III types are the mainly genetic types of organic matte...