No abstract

Abstract-The mechanical and pressure-sensitive properties of nano-Fe 2 O 3 cement paste were experimentally studied. The experimental results showed that, except at the 7-day age, the compressive strength of cement paste doped with different amounts of nano-Fe 2 O 3 measured at the 14-day and 28-day ages had a steady increase compared with the control group. All peak values of intensity appeared in adding amounts of nano-Fe 2 O 3 with 10 %. However, the increase of compressive strength at the 28-day age was less than those found at the 7-day and 14-day ages. The pressure-sensitivity was also progressively improved with the increase of adding amount of nano-

Abstract-This study explored the effect of adding different concentrations of carbon nanotubes (CNTs) on the resistance to chloride ions penetration of cement mortars through natural penetration of chloride ions and Mercury Intrusion Porosimetry. The experimental results of natural penetration of chloride ions showed that, the chloride ions penetration depth of the samples which added with CNTs were deeper than the control group which was without the addition of CNTs in the case of 35 days, 45 days, 55 days, 65 days of natural penetration of chloride ions, and the penetration depth increased with the content of CNTs. However, Mercury Intrusion Porosimetry (MIP) experimental results indicated that the porosity of cement mortar incorporated CNTs instead decreased, so the speculation that adding CNTs makes the porosity of the cement mortar specimens increase resulting in the increase of the penetration depth can be excluded. Another assumption was proposed that there may be a water film on the surface of the CNTs, and this water film can accelerate the penetrating speed of chloride ions as a convenient channel.

No abstract

No abstract