Compacting hot mixes asphalt (HMA) at low temperatures or mixing it in the asphalt at high temperatures is a constant source of concern to researchers, as compacting and mixing at non-ideal temperatures leads to adverse results, which negatively affect the properties of asphalt concrete and lead to problems paving.
This paper studies a practical laboratory process of the possibility of benefiting from an
important resource of the natural resources available in the country, namely "Basalt"
which is found in large quantities in the southern region (As-Suwayda)
to demonstrate
how much it meets the requirements of Standard Specifications for use in the manufacture
of concrete by testing five design mixtures of concrete , of which the cubic dimensions are
(15% x 15) cm and the cylindrical dimensions are (15 * 30 cm) with different percentages
of the basaltic and dolomitic calcareous compounds used in them as follows: (0% basalt
and 100% lime),( 25% basalt and 75% lime) , (50 % basalt 50 % lime) (75% basalt 25%
lime), (100%basalt and 0% lime) on the strength of pressure and tensile strain by
Splitting and Moduls of Elasticity of ages (28-7-3) days, and its effect on the behavior of
Reinforced Structural Elements susceptible to shear and Bending through testing
Reinforced beams of dimensions (16 × 12 × 200) cm on shear, Bending and cracking
Moduls (Coefficient) with ages of (14-28) days.
The aim of this study is improving the durability of precast products of Glass Fiber
Reinforced Concrete (GRC) and in the context of sustainability applications, reduction of
cement consumption and replacement of it with green materials. This study
has been done
to test the role of the natural pozzolan from Shihan Hill in As Suwayda as supplementary
cementing material by 10% -15% -20% - 25%, and to determine the effect of it on the
consistency and flexure strength over 180 days, as well as to test its role in improving the
micro-structure of the mixture by reducing the content of Ca(OH)2 and increasing C-S-H
& C-A-S-H gel, which were tested using X-Ray Diffraction (XRD) and Energy Dispersive
X-Ray (EDX) techniques, and as a result reduced the erosion of fibers as shown in images
by Scanning Electronic Electron Microscopy (SEM). Moreover the role of pozzolana has
been studied in controlling the degradation of the material over time which tested by
immersion in hot water 50° for 150 days and by drying – wetting cycles. Also the effect of
pozzolana on absorption, porosity and resistance of sulfates attacks was studied. The
results have shown that the used natural pozzolana has no negative effect on consistency or
mechanical properties, and it improved all the studied durability factors.
This paper studies a practical laboratory research of the possibility of utilizing the
natural resources available in the country, namely Basalt, which is available in large
quantities in the southern region (Al-Suwayda) in order to demonstrate the
extent to which
it meets the requirements of standard specifications for use in the manufacture of
(Reinforced) concrete by means of testing the resistance of pressure and tensile by
splitting and the elasticity coefficient of hardened (rigid concrete) at Different ages (3-7-
28) days.
As a result, pressure resistance tests increased by approximately 20 % with the
maturating period progress of concrete mixtures.
The pressure resistance of concrete mixtures prepared using basalt pebbles was
approximately 18% higher than the pressure resistance of concrete formed
usingcalcite(calcareous) pebbles in ages above 7 days
There was also a slight decrease of 8% in the split tensile resistance of the studied
samples prepared with basalt minerals , compared with the samples prepared using calcite
(calcareous) pebble and this resistance increases over time .
As for the elasticity coefficient , a 20% increase in the elasticity coefficient of the
concrete was noticed with the maturating of the concrete mixtures compared to the
referential mixture.
The behavior of the basaltic shear diaphragms of the remaining buildings of ancient times
was investigated as experimental research,and its resistance to natural factors and
horizontal loads resulting from wind and earthquakes,to take advantage of
them in the
maintenance of modern buildings,which are associated with floors and beams as horizontal
shear diaphragmsIn the hot and cold areas of the African continent, Asia and other similar
areas,to replace the reinforced concrete shear diaphragms,and metal shear diaphragms that
lose their resistance to the above factors. When the buildings are inspected, the vertical and
slanted slits resulting from the side loads are placed,it was found that the appearance of the
cracks related to the hardness of the shear diaphragm section, the basalt stone
specifications and the design of the shear diaphragm base.The research was conducted
to determine the durability, water permeability and resistance to pressure and tensile
strength of basalt stone samples used in historic stone buildings and their location in
laboratory methods.Horizontal loads resulting from seismic intensity were determined on
the front of the building at the tile level according to international requirements and
specifications.The method of calculating the basaltic shear diaphragms was
applied by applying arithmetic to build a basalt stone from several floors and a basement,
taking into account the characteristic resistance of basalt, depending on its density from
pressure and stretching and basalt stone in calculating.
The physical properties of gravel play an important role on the
quality of concrete industry in local workshops. Because they
constitute a main role in various concrete mix design. It's
necessary to understand the importance of the physical proper
ties
of gravel and It's improving role in the concrete mixes.
This research aimed to study the role of the properties of gravel
on the concrete mixes manufacture.
This article, will look at the structural development of the high
rise buildings and the factors that led to these developments, and so out
of the basic structural systems, even new classifications for
constructional systems (internal systems external systems), as well as
most construction systems deployed use.
This study presents definition of the types of lightweight concrete and
some studies, which use the volcanic scoria aggregates to produce
structural lightweight concrete.
Several concrete mixes were designed, and different tests were
performed to
determine its properties.
Ultra-High-performance concrete (UHPC) attracted attention in the civil engineering
industry in recent times, because it has high resistance and rigidity .
What provided the UHPC of skinny clips justifies using it in high buildings to take
advanta
ge of pressure and tensile its resistance .
The largest use of this material in the bridges because of its high resistance which
suitable for large loads as well as a valid treated outside the center and sustainability of the
high buildings, We study several models of building and we use this material in several
elements of these .
We found after analysis of the high efficiency of this models, especially in Diaframat.
Recently worldwide researches have been devoted to the use of steel fibers recovered from used tires in concrete. In Syria the amount of recovered steel from used tires is estimated about 6000 tons/year.
For this purpose a bead wire having a diamete
r of 0.8 mm from burnt tires was extracted and used. Three mixes with cement content 300- 350 -400kg/m3 were produced incorporating three different volumes of fiber 0.5%, 1.0%, and 1.5% and three different length 30-40-60 mm. The concrete obtained by adding these fibers evidenced a satisfactory improvement of the fragile matrix mostly in terms of toughness and post cracking behavior On the other hand it was improvements in compressive strength by steel fiber inclusion the interesting results confirm the promising application of concrete reinforced with steel fibers extracted from used tires in aircraft pavement hydraulic structures and ground slab in fabrics.
