This paper analyses the cause of early fracture of 20MnSi bars in tensile test by the methods of metallographic and scanning electron microscopes.

The early fracture of base cylinder for motorcycle vibration absorber was analyzed by electron probe microanalyzer(EPMA) and optical microscope.

When a blade is given to the scissors by abrasive wheel,the extremelly thick chromium-plating layer will carck and desquamate,thus leading to early fracture of surgical scissors in service.

The result suggests that the cavity beneath cement concrete pavement slabs and the overloading vehicles are the important factors of incipient fractures of cement concrete pavement slabs.

Analysis and calculation of temperature influence on the early stage crack of concrete wall;

The early stage crack and drying shrinkage crack of self-compaction concrete and pump concrete with water binder ratio is 0.

Analysis on prevention of early cracks in cement concrete pavement;

Owing to the early cracks in the premixed concrete,the paper analyzes its cause in terms ofproduction and construction and puts forward the countermeasures to be taken in the control pf production process.

Study on early-age cracking of high strength concrete under circumferentially restrained condition;

The effect of high concentration type naphthalene series(superplasticizer(H-UNF)),common type naphthalene series(superplasticizer(C-)UNF) and polycarboxylate type superplasticizer(PC) on early-age cracking and volume stability of cement mortar was investigated by means of multi-channel ellipse ring shrinkage cracking test,free shrinkage and strength test.

In this paper, tensile properties of high strength concrete (HSC) at earlyages were experimentally investigated with self-designed testing rig, andrelationships between early-age cracking and tensile properties werediscussed.