Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Porcelinite

Effect of Internal Curing on StrengthDevelopment of High Performance Concrete by Using Crushed Lightweight Porcelinite

Tareq S. Al-Attar; Adil M. Abdullatif; Ayman J. Al-Saad

Engineering and Technology Journal, 2014, Volume 32, Issue 11, Pages 2803-2814

High performance concrete, HPC, requires a low water-to-cementitious materials mass ratio w/cm and supplemental cementitious materials with silica fumes in the mixture, and use of a superplasticizer. Because of the low w/cm and rapid reaction at early ages, it becomes more difficult to provide curing water from the top surface and this water will be inadequate to satisfy the conventional curing. Therefore, there is a need to use internal curing that is supplied via internal materials, such as absorbent lightweight aggregate, which will be pre-saturated. The use of internal curing was investigated in this study by two ways. The first way was through the use of partial replacement of original coarse aggregate (gravel), meanwhile, the second was by replacing partiallythe original fine aggregate (sand)by crushed Porcelinite.The results showed that the fine Porcelinite replacement as internal curing material caused better enhancement instrengthof HPC than coarse Porcelinite. The replacement of original fine crushed Porcelinite caused an increase in compressive strength from 3.36 to 5.25percent, for splitting tensile strength from 5.48 to6.85 percent and for flexural strength from 11.76 to 12.74percent.

Behavior of Short Reinforced Porcelinite Concrete Columns Under Concentric Loads

Kaiss F. Sarsam; Ihsan A. S. Al-Shaarbaf; Mustafa S. Shuber

Engineering and Technology Journal, 2009, Volume 27, Issue 6, Pages 1219-1233

This study presents on experimental method to investigate the behavior of
reinforced porcelinite concrete columns subjected to concentric load. The experimental
work includes investigation of ten lightweight concrete columns with square cross
section 190×190mm and 1000mm in length subjected to concentric load to assess the
effect of the amount of longitudinal steel reinforcement, lateral tie reinforcement and
grade of concrete. From the experimental observation it was found that the porcelinite
aggregate is a good structural material to produce lightweight concrete columns. It is
noted from tested columns that keeping the amount of the longitudinal steel ratio
constant, the increase in the amount of transverse steel to about four times (by
decreasing the spacing to about a quarter according to the ACI-Code (318M-05)) gave a
significant influence on column post-cracking behavior. The improvements in the
column due to higher value of confinement include: (i) less brittle behavior; (ii)
significantly less damage to the concrete core; (iii) 12% increase in column load
carrying capacity. Also, A modified formula for column capacity is proposed to take
into account the influence of spacing of ties (effect of confinement).