Abstract
In recent years steel industry by-products and waste shell management become real
challenge due to their large amount, expensive management system and adverse effects
on environment. On the other hand the demands of the construction materials are
increasing day by day. Eco-mortar (made with recycled aggregate and eco-binder)
which has positive relation with reduction of environmental hazards can play a vital role
to save the environment and to continue the present construction activities.
The present study was an attempt to elucidate the effects of ground granulated blast
furnace slag (GGBFS) as partial replacement of ordinary Portland cement (OPC) and
oyster shell (OS) aggregate blended mortar on the strength properties in different
conditions and the effective use as pavement material. To know the effective usability of
the study materials, brightness, light irradiation in control and open natural condition,
spectrometric analysis and skid resistance test performed. Cylindrical samples (ф 5 cm ☑
10 cm) were used for the compressive strength test at 3, 7, 28 and 91 days. Blended
mortar was top filled on open graded asphalt concrete (30 cm × 30 cm × 5 cm) with
about 1 cm thickness by the help of vibrator. Total six types of mortar filled pavement
were used for brightness, light irradiation and skid resistance test to compare with
asphalt concrete pavement.
Slag could be used up to 85% as partial replacement of cement and 75% slag content
will give the highest strength for OS mortar. The compressive strength of river sand
(RS)-slag mortar could be lowered at initial stage but finally will increase about 17%
for 50% slag content than that of no slag mortar. At 28 days age, 30°C water curing
samples showed the highest strength for river sand mortar samples, and 20°C water
curing showed the highest compressive strength for OS mortar samples. Comparatively higher temperature is preferable for the high early strength of GGBFS blended mortar.
In brightness, light irradiation test and spectrometric analysis showed that ordinary
Portland cement (OPC)-Slag-OS sample is the brightest and highest solar reflector as
well as it showed lowest surface temperature within the study pavements. OPC-Slag-OS
blended mortar inserted pavement reduced highest surface temperature (16°C) in
compare with asphalt pavement. In terms of skid resistance property in wet condition,
OS mortar filled pavement could be used in walkways, parking area and other suitable
sites. Slag blended Eco-mortar could be used in pavement construction.