M. Mannan

A Study on Hardened State Properties of SCC using Fly Ash and Blended Fine Aggregate

The aim of this research is to investigate hardened state properties of Self Compacting Concrete (SCC) containing low calcium based fly ash. The mixtures were prepared using various proportions of Class F fly ash ranging from 0% to 30% cement replacement. Water to powder ratio is 0.38 – 0.39 and powder content was kept constant at 540 kg/m3. Properties investigated were strength properties (compressive strength and splitting tensile strength), and durability properties (complete immersion water absorption, apparent volume of permeable voids (AVPV), sorptivity, and RCIPT tests. These tests were done at various days. Results showed that fly ash replacement of up to 30% gave acceptable strength and durability properties for medium strength SCC.

Simultaneous Repair of Cleft Hard Palate by Vomer Flap along with Cleft Lip in Unilateral Complete Cleft Lip and Palate Patients

The purpose of the study was to see the short-term outcome of simultaneous repair of cleft lip and cleft hard palate with vomer flap against cleft lip repair alone in patients with unilateral complete cleft lip and palate (UCLP). A prospective observational study was carried out in 35 patients with unilateral complete cleft lip and palate who under-went cleft lip and cleft hard palate repair with vomer flaps simultaneously. After 3 months, cleft soft palate was repaired. During 1st and 2nd operations, the gap between cleft alveolus and posterior border of the cleft hard palate was measured. Postoperative complications, requirement of blood transfusion during the operation, and duration of operations were also recorded. Simultaneous repairs of cleft lip and closure of cleft hard palate with vomer flaps are easy to perform and are very effective for the repair of cleft lip and palate in UCLP patients. No blood transfusion was needed. Gaps of alveolar cleft and at the posterior border of hard palate were reduced remarkably, which made the closure of the soft palate easier, decreased operation time, and also decreased the chance of oronasal fistula formation.

Polishing resistance of polymer concrete pavement using limestone aggregate

ABSTRACT The purpose of this research was to investigate the polishing resistance of uncoated and resin-coated specimens under polishing and chemical attack. Low-quality aggregate, limestone and orthophthalic unsaturated polyester resin were the main materials. From the analysis, the macrotexture was reduced from the coarser aggregate to finer aggregate mix proportion. Resin-coated specimen was more polishing resistant than the uncoated specimen. Thickness reduction for resin-coated specimen was 1.8% after 9u2005h polishing, while the thickness reduction for uncoated specimen was 1.9% after 6u2005h polishing. In comparison with the uncoated specimen, the British pendulum number (BPN) of resin-coated specimen under dry and wet conditions was 8% higher and 16% lower, respectively. For the chemical resistant investigation, the immerging mediums used were water, sulphuric acid, sodium chloride, sodium hydroxide and used engine oil. The uncoated and resin-coated specimens were immersed into the solutions under direct immersion as well as wetting and drying for 24 weeks. Sulphuric acid and sodium hydroxide affected the BPN on both uncoated and resin-coated specimens but not for water and used engine oil, while sodium chloride only affected the BPN of the uncoated specimen.