Abstract: This work reports the potential of using Palm Kernel
(PK) ash and shell as a partial substitute for Portland Cement (PC)
and coarse aggregate in the development of mortar and concrete. PK
ash and shell are agro-waste materials from palm oil mills, the
disposal of PK ash and shell is an environmental problem of concern.
The PK ash has pozzolanic properties that enables it as a partial
replacement for cement and also plays an important role in the
strength and durability of concrete, its use in concrete will alleviate
the increasing challenges of scarcity and high cost of cement. In order
to investigate the PC replacement potential of PK ash, three types of
PK ash were produced at varying temperature (350-750C) and they
were used to replace up to 50% PC. The PK shell was used to replace
up to 100% coarse aggregate in order to study its aggregate
replacement potential. The testing programme included material
characterisation, the determination of compressive strength, tensile
splitting strength and chemical durability in aggressive sulfatebearing
exposure conditions. The 90 day compressive results showed
a significant strength gain (up to 26.2 N/mm2). The Portland cement
and conventional coarse aggregate has significantly higher influence
in the strength gain compared to the equivalent PK ash and PK shell.
The chemical durability results demonstrated that after a prolonged
period of exposure, significant strength losses in all the concretes
were observed. This phenomenon is explained, due to lower change
in concrete morphology and inhibition of reaction species and the
final disruption of the aggregate cement paste matrix.
Abstract: Numerous amounts of metallurgical dusts and sludge containing iron as well as some other valuable elements such as Zn, Pb and C are annually produced in the steelmaking industry. These alternative iron ore resources (fines) with unsatisfying physical and metallurgical properties are difficult to recycle. However, agglomerating these fines to be further used as a feed stock for existing iron and steelmaking processes is practiced successfully at several plants but for limited extent.
In the present study, briquettes of integrated steelmaking industry waste materials (namely, BF-dust and sludge, BOF-dust and sludge) were used as feed stock to produce direct reduced iron (DRI). Physical and metallurgical properties of produced briquettes were investigated by means of TGA/DTA/QMS in combination with XRD. Swelling, softening and melting behavior were also studied using heating microscope.
Abstract: Concrete durability as an important engineering property of concrete, determining the service life of concrete structures very significantly, can be threatened and even lost due to the interactions of concrete with external environment. Bio-corrosion process caused by presence and activities of microorganisms producing sulphuric acid is a special type of sulphate deterioration of concrete materials. The effects of sulphur-oxidizing bacteria Acidithiobacillus thiooxidans on various concrete samples, based on silica fume and zeolite, were investigated in laboratory during 180 days. A laboratory study was conducted to compare the performance of concrete samples in terms of the concrete deterioration influenced by the leaching of calcium and silicon compounds from the cement matrix. The changes in the elemental concentrations of calcium and silicon in both solid samples and liquid leachates were measured by using X – ray fluorescence method. Experimental studies confirmed the silica fume based concrete samples were found out to have the best performance in terms of both silicon and calcium ions leaching.
Abstract: The daily increase of organic waste materials resulting
from different activities in the country is one of the main factors for
the pollution of environment. Today, with regard to the low level of
the output of using traditional methods, the high cost of disposal
waste materials and environmental pollutions, the use of modern
methods such as anaerobic digestion for the production of biogas has
been prevailing. The collected biogas from the process of anaerobic
digestion, as a renewable energy source similar to natural gas but
with a less methane and heating value is usable. Today, with the help
of technologies of filtration and proper preparation, access to biogas
with features fully similar to natural gas has become possible. At
present biogas is one of the main sources of supplying electrical and
thermal energy and also an appropriate option to be used in four
stroke engine, diesel engine, sterling engine, gas turbine, gas micro
turbine and fuel cell to produce electricity. The use of biogas for
different reasons which returns to socio-economic and environmental
advantages has been noticed in CHP for the production of energy in
the world. The production of biogas from the technology of anaerobic
digestion and its application in CHP power plants in Iran can not only
supply part of the energy demands in the country, but it can
materialize moving in line with the sustainable development. In this
article, the necessity of the development of CHP plants with biogas
fuels in the country will be dealt based on studies performed from the
economic, environmental and social aspects. Also to prove the
importance of the establishment of these kinds of power plants from
the economic point of view, necessary calculations has been done as
a case study for a CHP power plant with a biogas fuel.
Abstract: The present research focus on the processing of mullite-based ceramics from oil refinery industrial wastes and byproducts of agricultural industry and on the investigating of silane modified surface of ceramics. Two waste products were used as initial material – waste aluminum oxide and waste rice husk. The burning - out additives used were waste rise husk. It is known that the oxide ceramics surface is hydrophilic due to the presence of – OH groups in it. The nature of ceramic surface regarding permeation of water and hydrocarbons can be changed by further treatment with silanes. The samples were studied mainly by X-ray analysis, FT-IR absorbance measurements and microscopic analysis. The X-ray analyses showed the phase composition depends on the firing temperature and on the purity of the starting alumina. Two kind of silanes were used for the transformation of surface from hydrophilic to hydrophobic – trimethoxymethylsilane (TMMS) and trimethylclorsilane (TMCS).
Abstract: Lightweight ceramic materials in the form of bricks
and blocks are widely used in modern construction. They may be
obtained by adding of rice husk, rye straw, etc, as porous forming
materials. Rice husk is a major by-product of the rice milling
industry. Its utilization as a valuable product has always been a
problem. Various technologies for utilization of rice husk through
biological and thermochemical conversion are being developed.
The purpose of this work is to develop lightweight ceramic
materials with clay matrix and filler of rice husk and examine their
main physicomechanical properties. The results obtained allow to
suppose that the materials synthesized on the basis of waste materials
can be used as lightweight materials for construction purpose.
Abstract: Climate change and environmental pressures are
major international issues nowadays. It is time when governments,
businesses and consumers have to respond through more
environmentally friendly and aware practices, products and policies.
This is the prime time to develop alternative sustainable construction
materials, reduce greenhouse gas emissions, save energy, look to
renewable energy sources and recycled materials, and reduce waste.
The utilization of waste materials (slag, fly ash, glass beads, plastic
and so on) in concrete manufacturing is significant due to its
engineering, financial, environmental and ecological benefits. Thus,
utilization of waste materials in concrete production is very much
helpful to reach the goal of the sustainable construction. Therefore,
this study intends to use glass beads in concrete production.
The paper reports on the performance of 9 different concrete
mixes containing different ratios of glass crushed to 5 mm - 20 mm
maximum size and glass marble of 20 mm size as coarse aggregate.
Ordinary Portland cement type 1 and fine sand less than 0.5 mm were
used to produce standard concrete cylinders. Compressive strength
tests were carried out on concrete specimens at various ages. Test
results indicated that the mix having the balanced ratio of glass beads
and round marbles possess maximum compressive strength which is
3889 psi, as glass beads perform better in bond formation but have
lower strength, on the other hand marbles are strong in themselves
but not good in bonding. These mixes were prepared following a
specific W/C and aggregate ratio; more strength can be expected to
achieve from different W/C, aggregate ratios, adding admixtures like
strength increasing agents, ASR inhibitor agents etc.
Abstract: Utilization of waste material in asphalt pavement
would be beneficial in order to find an alternative solution to increase
service life of asphalt pavement and reduce environmental pollution
as well. One of these waste materials is Polyethylene Terephthalate
(PET) which is a type of polyester material and is produced in a large
extent. This research program is investigating the effects of adding
waste PET particles into the asphalt mixture with a maximum size of
2.36 mm. Different percentages of PET were added into the mixture
during dry process. Gap-graded mixture (SMA 14) and PG 80-100
asphalt binder have been used for this study. To evaluate PET
reinforced asphalt mixture different laboratory investigations have
been conducted on specimens. Marshall Stability test was carried
out. Besides, stiffness modulus test and indirect tensile fatigue test
were conducted on specimens at optimum asphalt content. It was
observed that in many cases PET reinforced SMA mixture had better
mechanical properties in comparison with control mixture.
Abstract: In recent years demolished concrete waste handling and management is the new primary challenging issue faced by the countries all over the world. It is very challenging and hectic problem that has to be tackled in an indigenous manner, it is desirable to completely recycle demolished concrete waste in order to protect natural resources and reduce environmental pollution. In this research paper an experimental study is carried out to investigate the feasibility and recycling of demolished waste concrete for new construction. The present investigation to be focused on recycling demolished waste materials in order to reduce construction cost and resolving housing problems faced by the low income communities of the world. The crushed demolished concrete wastes is segregated by sieving to obtain required sizes of aggregate, several tests were conducted to determine the aggregate properties before recycling it into new concrete. This research shows that the recycled aggregate that are obtained from site make good quality concrete. The compressive strength test results of partial replacement and full recycled aggregate concrete and are found to be higher than the compressive strength of normal concrete with new aggregate.
Abstract: This work presents a low-cost and eco-friendly
building material named Agrostone panel. Africa-s urban population
is growing at an annual rate of 2.8% and 62% of its population will
live in urban areas by 2050. As a consequence, many of the least
urbanized and least developed African countries- will face serious
challenges in providing affordable housing to the urban dwellers.
Since the cost of building materials accounts for the largest
proportion of the overall construction cost, innovating low-cost
building material is vital. Agrostone panel is used in housing projects
in Ethiopia. It uses raw materials of agricultural/industrial wastes
and/or natural minerals as a filler, magnesium-based chemicals as a
binder and fiberglass as reinforcement. Agrostone panel reduces the
cost of wall construction by 50% compared with the conventional
building materials. The pros and cons of Agrostone panel as well as
the use of other waste materials as a raw material to make the panel
more sustainable, low-cost and better properties are discussed.
Abstract: General as well as the MSW management in Thailand is reviewed in this paper. Topics include the MSW generation, sources, composition, and trends. The review, then, moves to sustainable solutions for MSW management, sustainable alternative approaches with an emphasis on an integrated MSW management. Information of waste in Thailand is also given at the beginning of this paper for better understanding of later contents. It is clear that no one single method of MSW disposal can deal with all materials in an environmentally sustainable way. As such, a suitable approach in MSW management should be an integrated approach that could deliver both environmental and economic sustainability. With increasing environmental concerns, the integrated MSW management system has a potential to maximize the useable waste materials as well as produce energy as a by-product. In Thailand, the compositions of waste (86%) are mainly organic waste, paper, plastic, glass, and metal. As a result, the waste in Thailand is suitable for an integrated MSW management. Currently, the Thai national waste management policy starts to encourage the local administrations to gather into clusters to establish central MSW disposal facilities with suitable technologies and reducing the disposal cost based on the amount of MSW generated.
Abstract: Brick is one of the most common masonry units used as building material. Due to the demand, different types of waste have been investigated to be incorporated into the bricks. Many types of sludge have been incorporated in fired clay brick for example marble sludge, stone sludge, water sludge, sewage sludge, and ceramic sludge. The utilization of these waste materials in fired clay bricks usually has positive effects on the properties such as lightweight bricks with improved shrinkage, porosity, and strength. This paper reviews on utilization of different types of sludge wastes into fired clay bricks. Previous investigations have demonstrated positive effects on the physical and mechanical properties as well as less impact towards the environment. Thus, the utilizations of sludge waste could produce a good quality of brick and could be one of alternative disposal methods for the sludge wastes.
Abstract: In this study the effect of incorporation of recycled
glass-fibre reinforced polymer (GFRP) waste materials, obtained by
means of milling processes, on mechanical behaviour of polyester
polymer mortars was assessed. For this purpose, different contents of
recycled GFRP waste powder and fibres, with distinct size gradings,
were incorporated into polyester based mortars as sand aggregates
and filler replacements. Flexural and compressive loading capacities
were evaluated and found better than unmodified polymer mortars.
GFRP modified polyester based mortars also show a less brittle
behaviour, with retention of some loading capacity after peak load.
Obtained results highlight the high potential of recycled GFRP waste
materials as efficient and sustainable reinforcement and admixture for
polymer concrete and mortars composites, constituting an emergent
waste management solution.
Abstract: Hydrogen is regarded to play an important role in
future energy systems because it can be produced from abundant
resources and its combustion only generates water. The disposal of
waste tyres is a major problem in environmental management
throughout the world. The use of waste materials as a source of
hydrogen is particularly of interest in that it would also solve a waste
treatment problem. There is much interest in the use of alternative
feedstocks for the production of hydrogen since more than 95% of
current production is from fossil fuels. The pyrolysis of waste tyres
for the production of liquid fuels, activated carbons and gases has
been extensively researched. However, combining pyrolysis with
gasification is a novel process that can gasify the gaseous products
from pyrolysis. In this paper, an experimental investigation into the
production of hydrogen and other gases from the bench scale
pyrolysis-gasification of tyres has been investigated. Experiments
were carried using a two stage system consisting of pyrolysis of the
waste tyres followed by catalytic steam gasification of the evolved
gases and vapours in a second reactor. Experiments were conducted
at a pyrolysis temperature of 500 °C using Ni/Al2O3 as a catalyst. The
results showed that there was a dramatic increase in gas yield and the
potential H2 production when the gasification temperature was
increased from 600 to 900 oC. Overall, the process showed that high
yields of hydrogen can be produced from waste tyres.
Abstract: Composting is the process in which municipal solid
waste (MSW) and other organic waste materials such as biosolids
and manures are decomposed through the action of bacteria and other
microorganisms into a stable granular material which, applied to
land, as soil conditioner. Microorganisms, especially those that are
able to degrade polymeric organic material have a key role in speed
up this process. The aim of this study has been established to
isolation of microorganisms with high ability to production
extracellular enzymes for degradation of natural polymers that are
exists in MSW for decreasing time of degradation phase. Our
experimental study for isolation designed in two phases: in first
phase we isolated degrading microorganism with selected media that
consist a special natural polymer such as cellulose, starch, lipids and
etc as sole source of carbon. In second phase we selected
microorganism that had high degrading enzyme production with
enzymatic assay for seed production. However, our findings in pilot
scale have indicated that usage of this microbial consortium had high
efficiency for decreasing degradation phase.
Abstract: The daily increase of organic waste materials resulting
from different activities in the country is one of the main factors for
the pollution of environment. Today, with regard to the low level of
the output of using traditional methods, the high cost of disposal
waste materials and environmental pollutions, the use of modern
methods such as anaerobic digestion for the production of biogas has
been prevailing. The collected biogas from the process of anaerobic
digestion, as a renewable energy source similar to natural gas but
with a less methane and heating value is usable. Today, with the help
of technologies of filtration and proper preparation, access to biogas
with features fully similar to natural gas has become possible. At
present biogas is one of the main sources of supplying electrical and
thermal energy and also an appropriate option to be used in four
stroke engine, diesel engine, sterling engine, gas turbine, gas micro
turbine and fuel cell to produce electricity. The use of biogas for
different reasons which returns to socio-economic and environmental
advantages has been noticed in CHP for the production of energy in
the world. The production of biogas from the technology of anaerobic
digestion and its application in CHP power plants in Iran can not only
supply part of the energy demands in the country, but it can
materialize moving in line with the sustainable development. In this
article, the necessity of the development of CHP plants with biogas
fuels in the country will be dealt based on studies performed from the
economic, environmental and social aspects. Also to prove the
importance of the establishment of these kinds of power plants from
the economic point of view, necessary calculations has been done as
a case study for a CHP power plant with a biogas fuel.