Modern Construction Materials PDF

Modern Construction Materials (Subject Code: CE761) Topic of Presentation Lightweight Aggregate Concrete With Palm Oil Shells Dr. B. P. Sharath Contract Faculty Dept. of Civil Engineering, NITT  PALM FRUIT Hard Shell...

Modern Construction Materials (Subject Code: CE761) Topic of Presentation Lightweight Aggregate Concrete With Palm Oil Shells Dr. B. P. Sharath Contract Faculty Dept. of Civil Engineering, NITT  PALM FRUIT Hard Shell Outer Skin Known as Oil Palm Shell Provides Palm Oil Processing of Palm Fruit Generates Wastes Like Source for Palm Kernel Oil Empty Bunches of Fruits Palm Oil Fibre Palm Oil Effluent Palm Oil Shell  THINGS FROMPALM TREE PLAM OIL SHELLS  Introduction on Palm Oil Shells As Potential LW’ s Palm oil shells are a renewable and abundant biomass residue obtained from the extraction of palm oil from palm fruits. They are a byproduct of the palm oil industry, which is prevalent in tropical regions. These shells are typically discarded or burned as waste, contributing to environmental pollution and greenhouse gas emissions. Lightweight Nature Palm oil shells possess a low bulk density, making them ideal for use as lightweight aggregates in concrete. Their lightweight nature helps reduce the overall density of concrete, resulting in structures with lower dead loads  Introduction on Palm Oil Shells As Potential LW’ s Porosity Palm oil shells have a porous structure, which contributes to the lightweight properties of concrete while also providing good insulation against heat and sound. Sustainability Utilizing palm oil shells as a lightweight aggregate helps to reduce waste from the palm oil industry and promotes sustainability in construction practices. This sustainable approach aligns with global efforts to promote eco-friendly construction practices and mitigate the environmental footprint of the construction industry.  Potential Threats to Environment From Palm Oil Shells Improper Disposal If palm shells are not utilized and end up in landfills, they decompose anaerobically producing methane which is a greenhouse gas. Open dumping and burning also causes pollution. Resource Depletion Over-exploitation of palm shells as aggregate without recycling or replenishing supplies may deplete this resource over time. Deforestation and Habitat Loss Increased palm oil production to meet aggregate demand may potentially drive deforestation for new palm plantations resulting in loss of habitats etc  Potential Threats to Environment From Palm Oil Shells Carbon Emissions Palm cultivation, transport of shells, and concrete production using shells causes significant carbon emissions contributing to climate change impacts. Water Contamination Palm oil mill effluent containing residues from shell processing can contaminate nearby water bodies like rivers and groundwater if improperly treated. Air Pollution Dust from shell processing and concrete batching plants can contribute to air pollution. Thermal processing of shells also causes air emissions.  Background of Utilization of Palm Oil Shells as LWA’ s Global palm oil production has increased dramatically from 15 million tons in 1995 to over 70 million tons today. This has resulted in abundant supplies of palm oil biomass waste, especially in major producing countries like Indonesia and Malaysia. Research on using processed palm shells as aggregate replacement has gained momentum in past 15 years or so. Still it is ongoing to optimize mixtures. Applications like lightweight concrete blocks, wall panels, and insulation can benefit from using palm shells as aggregate.  Manufacturing Process of Palm Oil Shell As Aggregates Step 1: Palm Oil Shell Preparation a) Shells are first washed and cleaned to remove any remaining palm oil residues. b) They are then crushed into smaller pieces of 10-20 mm size using mechanical crushers. Step 2: Heating/Thermal Treatment a) The crushed shells may be subjected to controlled heating at temperatures ranging from 300-800° C. b) This helps increase shell hardness, reduce moisture absorption, and remove organic impurities. Step 3: Grinding a) Heated shells are further ground into a uniform granular consistency resembling coarse sand. This creates the aggregates.  Manufacturing Process of Palm Oil Shell As Aggregates Step 4: Screening and Separation a) The lightweight aggregate is sieved into different particle size distributions if required. b) Magnetic separators may be used to remove any contaminating metals. Step 5: Testing and Quality Control a) Sample testing is conducted on the finished aggregate to check properties like particle shape, gradation, density, moisture content, organic impurities, etc. Step 6: Storage and packaging a) The manufactured lightweight aggregate is stored in silos or  Properties of Palm Oil Shells Aggregates Physical Properties a) Low particle density - around 0.5-0.7 g/cm3 compared to 2.5-2.7 for conventional aggregates b) High internal porosity gives low bulk density c) Hard and durable - resist crushing forces d) Dry shells have natural water repellence which reduces water absorption Chemical Properties a) Contains organic compounds like lignin and cellulose b) Low silica content compared to normal aggregates c) Absorbs water when immersed over long time  Manufacturing Process of Palm Oil Shell Aggregates in Lightweight Aggregate Concrete Mix design considerations a) Palm shell aggregates have lower specific gravity compared to natural aggregates. This is accounted for in mix design calculations. b) Cement content and water/cement ratios are adjusted to achieve target strength. More cement may be needed. c) Admixtures like fly ash or silica fume help improve strength and workability. Mixing process a) Palm shell aggregates are combined with cement, sand, water and any admixtures using a concrete mixer. b) Mixture is tested for workability using slump test. Adjustments made if needed.  Manufacturing Process of Palm Oil Shell Aggregates in Lightweight Aggregate Concrete Casting and curing: a) Fresh concrete mixture is cast into molds or formwork. b) Adequate compaction ensures there are minimal voids. c) Curing done by water spraying or steam treatment to maximize strength. Quality control checks: a) Fresh concrete tests include slump, unit weight to check density. b) Hardened concrete tests check compressive strength, water absorption. c) Core samples may be taken from finished products for further testing.  Properties of LWAC produced with Palm Oil Shell Based Aggregates Mechanical Properties a) Density Dry density ranges from 1600-2000 kg/m3 15-25% lower than conventional concrete Reduces dead load on structures b) Compressive Strength Can achieve upto 17 to 35 Mpa Lower than conventional concrete Adequate for non-structural applications Can be improved with higher cement content and curing  Properties of LWAC produced with Palm Oil Shell Based Aggregates Mechanical Properties c) Tensile & Flexural Strength Tensile strength about 10-15% of compressive strength Flexural strength around 3-7 MPa Water Absorption Absorbs more water due to porous aggregate Ranges from 6-20% by weight Reduces durability against environmental exposure  Properties of LWAC produced with Palm Oil Shell Based Aggregates Thermal Properties a) Offers enhanced thermal insulation properties due to the low thermal conductivity of palm oil shells b) This results in reduced heat transfer through the concrete, leading to energy savings in buildings and improved thermal comfort for occupants. Durability and Resistance to Environmental Factors a) Demonstrates good durability and resistance to environmental factors such as freeze-thaw cycles, sulfate attack etc. b) Porous structure of palm oil shells enhances the concrete's resistance to chemical attack and moisture ingress, prolonging its  Effect of Aggregate Sizes on Strength Properties of LWAC With Palm Oil Shells Palm shell aggregate size affects bonding with cement paste matrix and interlocking between aggregates. This influences strength. Smaller aggregate sizes provide more surface area for bonding. However, excessive fines can increase water demand and reduce workability. Larger aggregate sizes improve interlocking which enhances tensile and flexural strengths. But very large sizes can create stress concentrations and weak points. Using a wide range of sizes improves particle packing density. But gradation must be optimized, too many fines or oversized particles  Effect of Aggregate Sizes on Strength Properties of LWAC With Palm Oil Shells Many research results have shown a graded combination of coarse (10-20mm), medium (5-10mm) and fine (2-5mm) fractions provides optimal strength. Single-sized aggregates result in lower compressive strength compared to graded combinations. Aggregates between 5-10mm size seem ideal. Smaller sizes may crush under loading. Larger sizes don't improve strength significantly. Overall, a good gradation of aggregate sizes is needed to maximize density and strengths. Very fine or coarse fractions should be limited.  Applications of Palm Shell Aggregate Concrete Non-structural precast products Lightweight concrete blocks for wall partitions and landscaping Concrete masonry units for non-loadbearing walls Low density reduces handling costs Insulation and sound absorption Floating marine structures like pontoons and platforms Partition and facade panels for thermal insulation Noise barriers and acoustic treatments  Applications of Palm Shell Aggregate Concrete Sustainable building materials Residential and commercial buildings Schools, hospitals, low-cost housing Reduces structure loads and foundation costs Geotechnical applications Lightweight backfill material instead of soil Retaining walls, bridge abutments, embankments Reduces lateral earth pressures Emerging uses 3D printable concrete High performance panels with improved strength Development of structural lightweight concrete  Benefits of Using Palm Oil Shell in LWAC Environmental Sustainability Helps reduce the environmental impact of the construction industry by repurposing a waste byproduct from the palm oil industry. Resource Conservation Reduces the demand for natural aggregates thereby conserving natural resources and minimizing ecosystem disruption associated with aggregate extraction. Energy Efficiency Offers improved thermal insulation properties, leading to enhanced energy efficiency in buildings and infrastructure.  Benefits of Using Palm Oil Shell in LWAC Cost-Effectiveness Often available at low or no cost, making them a cost-effective alternative to conventional lightweight aggregates in concrete production. Enhanced Sustainability Credentials Enhances the sustainability credentials of construction projects, contributing to green building certifications and environmental rating systems. Usage of sustainable materials like LWAC with palm oil shells may qualify for incentives, grants etc. aimed at promoting sustainable construction practices.  A Case Study With Respect to Usage of Palm Oil Shell Aggregate Concrete Low-Cost Housing Project in Malaysia Small Structure Made With Palm Oil Shell Aggregate Low Cost Housing Using Palm Oil Shell Concrete Aggregate Concrete  A Case Study With Respect to Usage of Palm Oil Shell Aggregate Concrete In 2007, a low-cost housing project was constructed in Johor, Malaysia using lightweight palm oil clinker concrete for the walls and structural elements. Palm oil clinker is a processed waste product from palm oil fuel boilers, mainly comprising palm oil shells and fibers. The clinker was crushed and ground into aggregate to replace natural aggregates in the concrete mix. Over 3000 housing units were constructed using walls and slabs made from the oil palm clinker lightweight concrete.  A Case Study With Respect to Usage of Palm Oil Shell Aggregate Concrete The density of the concrete was 1850 kg/m3 compared to 2400 kg/m3 for conventional concrete. Compressive strength ranged from 17 to 25 MPa, meeting strength requirements. Using the lightweight concrete resulted in an approximately 15% reduction in the dead load of the structures compared to normal concrete, enables savings in reinforcement and foundation requirements. The project demonstrated that palm oil waste can be viably used to produce sustainable and cost-effective concrete for housing  Challenges and Considerations With Usage of Palm Oil Shell Aggregate Concrete Lower Strength Exhibits lower compressive and tensile strength compared to conventional concrete. This restricts usage to non-structural applications. Variable Properties Shells from different sources can exhibit variability in properties which affects concrete performance. Higher Water Absorption Porous shell structure leads to greater water absorption which reduces durability and strength. Pre-treatment of shells is required.  Challenges and Considerations With Usage of Palm Oil Shell Aggregate Concrete Lack of Standards Need to develop codes and standards related to mix design, testing methods and performance criteria for palm shell concrete. Storage and Pre-processing Need proper storage and pre-processing like crushing, grinding, screening etc. which adds to costs. Residual Waste Shells may contain residual palm oil and other impurities that can impact quality and environmental factors.  Advancements In Usage of Palm Oil Shells in LWAC Hybrid aggregates Combining palm shells with other artificial or waste aggregates to optimize particle packing density and reduce voids Chemical treatments Using chemical treatments like acids or other coatings to modify the shell surface and reduce water absorption. This would improve durability. Nanomaterials Incorporating nanomaterials like nano-silica can enhance the interfacial transition zone (ITZ) between the shell aggregate and cement paste.  Advancements In Usage of Palm Oil Shells in LWAC Fibers Adding discreet fibers or fiber-reinforced palm shell aggregates can better control cracking and improve structural behavior. Digital fabrication 3D printing and digital construction methods to create innovative palm shell LWAC shapes and architecture. Advanced mixing Using techniques like vacuum or pressure mixing to fabricate LWAC with lower voids and higher density.  Some Observations from Scanning Electron Microscopic Image Voids and cracks illustrated the weak bond between OPS-cement paste interfaces The reduction in the strengths of has been largely attributed to the breakdown of the weaker bond between Palm Oil Shell and cement paste because of the smooth surface and the presence of micro pores on the outer surface of Palm Oil Shell.