This article discusses reliability probability,failure probability of compressive strength of mortar specimens and influence of the failure probability upon compressive strength of brick masonry.

Results show that: the ability on preventing mortar from carbonation of the mortar specimens with cracks is improved after electrodeposition with the ZnSO_4 and MgSO_4 solutions, and it is improved more with the latter one.

The mortar specimens with cracks are repaired with the ZnSO_4 and MgSO_4 solutions, in the process carbonation depth of the mortar specimens with cracks is measured at the non-cracked and cracked part after the ages of 7d,14d,21d,28d and 35d, and carbonation depth of mortar specimens with cracks studied after electrodeposition.

We performed dynamic tests and studied the dynamic properties under compression of dry and wet cement mortar specimens using the Hopkinson split pressure bar method.

A stress level of 0.2 N/mm2 is insufficient to suppress the growth of the mortar (in the original mortar specimens as well as in the specimens fired at the test temperature for a period of 10 h).

Mortar specimens of cement are prepared with these additives.

Polyurethane coated OPC mortar specimens exposed to 1M NaCl solution were studied by impedance spectroscopy and SEM over a period of 4 years.

The formation of hexagonal chloroaluminates in mortar specimens pre-cured at 20, 40 and 60°C for two weeks and stored in a 0.5 M NaCl solution for up to 255 days has been studied.

The cement mortar specimens with a central slits are tested under uniaxial com-pression.The test results show that tensile cracks initiate,as a rule near the tip and may propagatesteady for a certain length.Mean while shear fructures appear and propagate slowly to the failurestate in the zone of compressive stress concentration. So the fracture strength of rock under compres-sion might be differentiated into the initial tensile strength,the peak strength and residual strength.

The effect of fly-ash with high percent of loss on ignition(12. 8%) on the strength of mortar was investigated. Two series mortar specimens with different content of fly-ash from weight of cement were tested. The water requirement of fly-ash mortars increases as fly-ash content increases. The mixes containing fly-ash show a greater increase in compressive strength and flexural strength after heat-humidity processing, than the OPC mixes. The mix containing 30% fly-ash from weight of cement shows maximum...

The effect of fly-ash with high percent of loss on ignition(12. 8%) on the strength of mortar was investigated. Two series mortar specimens with different content of fly-ash from weight of cement were tested. The water requirement of fly-ash mortars increases as fly-ash content increases. The mixes containing fly-ash show a greater increase in compressive strength and flexural strength after heat-humidity processing, than the OPC mixes. The mix containing 30% fly-ash from weight of cement shows maximum compressive strength and flexural strength. The mixes containing more than 30% fly-ash, keeping 28 days in the normal condition, show decrease of compressie strength and flexural strength,compared with OPC mortar.

In order to setup a calculation method for the elastic modulus of stone masonry,experiments were carried out on stone building blocks and mortar specimens. Firstly, strain stress curves were obtained from 10 sheet stone building block and 10 block stone building block specimens.Combined with the domestic achievements in this field, calculation formulae for elastic modulus and initial elastic modulus of stone building block were constructed ,which agree with the experimental results quite well....

In order to setup a calculation method for the elastic modulus of stone masonry,experiments were carried out on stone building blocks and mortar specimens. Firstly, strain stress curves were obtained from 10 sheet stone building block and 10 block stone building block specimens.Combined with the domestic achievements in this field, calculation formulae for elastic modulus and initial elastic modulus of stone building block were constructed ,which agree with the experimental results quite well. Secondly, through analyzing elastic modulus from 24 cement mortar specimens of 4 groups, calculation formulae for elastic modulus of cement mortar were set up.There are good agreements between calculation and experimental results. On the basis of the above analysis, a new way and the corresponding formula to evaluate the elastic modulus of stone building block were established. Finally, applicable formulae for stone masonry in railway structural engineering were given.