Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : preparation

Optimization Conditions for Preparation Of Polyvinyl Alcohol- Alumina Gel Composite and its Properties


Engineering and Technology Journal, 2010, Volume 28, Issue 20, Pages 6115-6127

A preparation of poly (vinyl alcohol) (PVA)/alumina (Al 2O3) gel
composite was investigated.
This type of composite gel was carried out with two stages firstly the
hydrolysis of polyvinyl alcohol in a hot water at 200ºC for 2 hours and different
mixing ratio of (PVA/H2O) solution at (10,20,30,40,50) wt% has been
investigated to check its operating conditions .Secondly different ratios of alumina
refractory were used (5,10,15,20,25) wt% of (AL2O3 /PVA) at 350ºC for 4 hours
to give a completes composite gel of ( PVA/Al2O3) in a polymerization stage.
The final composite gel of (Al2O3/PVA) is molded in a different shapes
and size due to suitable characteristics tests in order to check chemical, thermal,
and mechanical properties afterward curing these specimens at 120ºCfor 2 hours
to complete the compatibility of composite gel.
The results tests proved that: All final composite gel specimen is more
efficient than other base polyvinyl alcohol (PVA) of high mechanical and thermal
properties than base one with less internal stresses, also the resistance for chemical
solutions in (100%H2O, 10%H2SO4) is increased at sever conditions at 50ºC for
5 days especially for optimum mixing ratio specimen No.3 with preference for
optimum sample No.3 of (30%PVA Sol./15% Al2O3) g/g.

Optimization of Asphalt Mix Improved by the Addition of Scrap Tires

Raghad O. Abass; Mohammed O. Abass; Falak O. Abass

Engineering and Technology Journal, 2009, Volume 27, Issue 12, Pages 2425-2446

The design of improved asphalt mix is achieved by the use of three major
variables , weight of scrap tires replaced by coarse base aggregate , particles size of scrap tires finally the weight of binder used (bitumen). The improved asphalt mix (IAM) requires a balance between rut
resistance and durability to resist cracking and moisture damage (stripping) .Accordingly several factors that influence rut resistance and durability are considered during the design process: The mix consisted of binder (3.0-6.5) %wt. , scrap tires (10-30) wt% with
particle size of (1-5) cm , is achieved by the application of box-Wilson design program. The improved mix is achieved by the use of both hot (wet) and cold (dry) processes for preparing the standard mix firstly under high temperature 168˚C with a continuous mixing for 2 hours then mould this hot mixture in standard molder found with the replacement of a coarse percent of aggregate by the different sizes of scrap tires (1-5)cm by the use of cold ( dry) technique , finally a
compression step is achieved with 52 hut for 20 min for both sides of molder in order to compress the prepared specimens then leaved for 24 hrs from the stability of specimens before any tests applied .
The results of selected variables are studied for prepared specimens to
check different important properties (mechanical, physical, chemical, thermomechanical and thermo-physical properties), then applied these result properties data in analytical computer programme software to check its fitting to design model selected and calculated the optimum properties and optimum variables for improved asphalt mix. After-ward the computerize analysis results shows that an optimum mix No.(11) reached high stability and flexibility, also gave excellent physical and
chemical properties as shown in present work below. Also described in this work the application and comparison between standard and improved optimum asphalt mix.