Seaweed Biocomposite as a Green Construction Material

A project thesis submitted to the Civil Engineering program Universiti Teknologi PETRONAS as partial fulfillment of the requirement for This research aims to determine the compressive strength of mortar cubes based on a replacement ratio of 5% & 15% of seaweed (Gracilaria species). Later, the samples were oven dried at 105C for 24 hours and some continue to be fired at 600C for 3 hours to obtain the sample in granular and powder form.

The water absorption test used to determine the total volume of the permeable void will also be described. The sample was then embedded in mortar and the compressive strength was determined after 3, 7, 14 and 28 days. Therefore, seaweed, which is environmentally friendly, can act as a substitute for green building materials.

With this research project under her supervision, she enabled me to continue my studies. Not to forget, thanks to my FYP coordinators, Drs. Zulaikhi and Dr. Ehsan, for helping to carry out this research project smoothly and on time and for guiding me through all the submissions.

INTRODUCTION

BACKGROUND OF STUDY
PROBLEM STATEMENT
OBJECTIVES
SCOPE OF STUDY
SIGNIFICANCE OF STUDY

Cement is never an environmentally friendly material despite the fact that it contributes a significant weight in the construction industry. A huge amount of cement is used to achieve higher concrete strength, while a small amount of seaweed added to the concrete mix is believed to bring the concrete strength up to a slightly above level. During mass production of seaweed reinforced concrete, a lot of money can be saved without compromising the quality of the mortar.

However, the main reason for using seaweed is to provide a new alternative to the mortar industry so that cement production can be gradually reduced. The aim of this study is to come up with a better quality of seaweed modified mortar than the conventional one while reducing the harmful effect of excess carbon dioxide on our dear mother earth. To determine the compressive strength of mortar based on a range of percentage replacement of seaweed in the mortar (5% & 15%).

The cement replacement materials were included in the mix design and were later added in the batch process. Several tests will be carried out with mortar with different ratio of seaweed as replacement to investigate the importance of seaweed in mortar in terms of compressive strength, thermal property and water storage capacity.

Figure 1 : Global Carbon Dioxide Emission. Source : [1]

LITERATURE REVIEW

PRETREATMENT OF NATURAL POLYMER
NATURAL FIBERS TO REINFORCE THE BIOCOMPOSITE
APPLICATION OF SEAWEED IN CONSTRUCTION INDUSTRY
SEAWEED AS A FILLER IN BIOCOMPOSITE
NATURAL FIBRES TO REINFORCE THE BIOCOMPOSITE
MECHANICAL PROPERTIES OF NATURAL FIBER
FACTORS INFLUENCING THE PERFORMANCE OF BIOCOMPOSITE

There are three categories of natural fibers for reinforcing concrete, namely animal-based, mineral-derived and plant-based. The properties of natural fibers vary considerably depending on chemical composition and structure, which relate to fiber type as well as growing conditions, harvest time, extraction method, processing and storage procedures. Due to the incessant discharge of 𝐶𝑂2 to the earth, exploits the production of natural seaweed in the seas and oceans.

The mechanical properties of cellulose determine the high potential of natural fibers in load bearing situations. According to the studies done by several authors (eg Gassan et al), the elastic modulus falls in the range of 40-80 Gpa (depending on the chosen theoretical modulus for cellulose) for most natural fibers in biocomposite. Realistically, the highest fiber volume ratio is around 70% due to manufacturing parameters and is usually in the range of 50% to 65% [38].

Adding too little fiber reinforcement in the composite will actually weaken the properties of the material. The elastic modulus of a composite in the fiber direction of a unidirectional composite can be calculated using the following equation.

Table 5 : Commercialized major fibre source. Source : [16]

METHODOLOGY

PROJECT PLAN
INTEGRATED METHODOLOGY
X-RAY DIFFRACTION (XRD) EXPERIMENT
BRUNAUER, EMMETT AND TELLER (BET)
MORTAR MIXING AND MIX DESIGN
ASTM FOR WATER ABSORPTION
KEY PROJECT MILESTONES

Stage 4, the compressive strength of the seaweed-modified mortar was determined and characterization tests were conducted by Central Analytical Lab to support the findings. This is to ensure that the surface of the seaweed sample comes into contact with the acid, to break down the lignin layer (cell wall) that surrounds the seaweed sample. The seaweed was immersed in 6 liters of 0.1 M HCL that we previously diluted in a bucket which was then placed in a fume hood for 24 hours.

The seaweed was then weighed on an aluminum tray before being placed in the oven for drying purposes at 105℃ for 24H. It was then dried in the sun for 3 days in the open air where the environment is free of dust to avoid the contamination of the seaweed. First, the seaweed was collected from the fisheries department in Pulau Sayak, Kota Kuala Muda, Kedah.

The seaweed was washed in batches to remove impurities and neutralize the pH [43]. The weight of the sample before and after it was oven dried was recorded to calculate the moisture content of the water. After the oven drying, a part of the oven-dried sample was taken for characterization tests and later used directly in mortar mix, while another batch of the oven-dried sample was transferred to acid treatment with 0.1 M hydrochloric acid (HCl).

5 liters of HCl are mixed with 100 g of the oven-dried sample for 24 hours under standard room temperature to ensure that the sample surfaces are fully in contact with acid to break down the cell wall or lignin layer surrounding the seaweed. The specific surface area of a powder is determined by physical adsorption of a gas on the surface of the solid and by calculating the amount of adsorbate gas corresponding to a monomolecular layer on the surface. Physical adsorption is due to relatively weak forces (Van Der Waals forces) between the adsorbate gas molecules and the adsorbing surface area of the test powder.

Because of the added polymer on one pan, the heating rate of one pan will somehow be slower than the other. This is because the pan with extra material will take more heat to keep the temperature of the test pan rising at the same rate as the reference pan. The pore structure of a cement paste matrix provides access to the transport of liquid into concrete, and its development depends on a number of factors, including the properties and composition of the concrete constituents, the initial setting state and its duration, the age at testing, and the climatic exposure during drying and conditioning of the concrete.

RESULTS AND DISCUSSION

MOISTURE CONTENT AND pH

The seaweed is divided into several batches to be washed and their pH and moisture content recorded.

COMPRESSIVE STRENGTH TEST

Therefore, all comparisons will be made with respect to the mix control of 0.45, also known as C.45; After 7 days, none of our samples can exceed the compressive strength of control mortar. However, the highest compressive strength generated in our sample on the 7th day would be the mortar processed with 5% (17.19 Mpa) seaweed ash followed by Mpa). At 15% replacement of cement with seaweed ash, the compressive strength generated after 28 days is 29.9 Mpa, which is slightly higher than the conventional concrete at 29.6 Mpa.

It is noted that the sample with 5% seaweed ash produces the closest compressive strength to the control mixture at 28.79 Mpa. Undoubtedly, the mortar processed with seaweed in ash form at 5% substitution outperforms the sample in granular form in terms of compressive strength. It is worth noting that all samples are weaker than the control compressive strength after 14 days, except the sample containing 15% seaweed ash.

Figure 8 : Compressive Strength for control mix w/c 0.45

ASTM WATER ABSORPTION TEST C-642-97

It can be seen that the mortar containing up to 15% seaweed ash has the lowest percentage in terms of volume of permeable voids, which is 16.95%. On the contrary, the mortar with the same amount of fillers but in granular form shows the highest volume of permeable voids, namely 39.5%. Both samples incorporating the ash form of seaweed show a similar result with a difference of 2.07%.

In comparison, the mortar filled with 15% seaweed ash shows the smallest deviation from the control mortar at 2.27%.

BRUNAUER, EMMETT AND TELLER (BET)

FIELD EMISSION – SCANNING ELECTRON MICROSCOPE

DIFFERENTIAL SCANNING CALORIMETRY (DSC) THERMAL

XRD TEST RESULT

CONCLUSION

Muthadhi, “A review on the application of seaweed in the construction industry,” International Journal of Emerging Technology and Advanced Engineering, vol. Hernández-Carmona, “Effect of alkali treatment time and extraction time on Gracilaria vermiculophylla agar,” Journal of Applied Phycology, journal article vol. Ding, “Effect of process conditions on gel viscosity and gel strength of semi-refined carrageenan (SRC) produced from seaweed (Kappaphycus alvarezii),” Journal of King Saud University - Engineering Sciences , vol.

Wu, “Evaluation of the statistical strength of bamboo fiber and mechanical properties of fiber-reinforced green composites,” Journal of Central South University of Technology, journal article vol. Panigrahi, “Chemical Treatments of Natural Fibers for Use in Natural Fiber Reinforced Composites: A Review,” Journal of Polymers and the Environment, journal article vol. Kim, “Seaweed Pretreatment Effects on the Thermal and Mechanical Properties of Seaweed/Polypropylene Biocomposites,” Composites Part A: Applied Science and Manufacturing, vol.

Cheikh, "Influence of Fiber Orientation and Volume Fraction on the Tensile Properties of Unidirectional Alpha-Polyester Composite". Gashti, "Effect of colloidal dispersion of clay on some properties of wool fibers", Journal of Dispersion Science and Technology, vol. Sarasini, "Tensive behavior of New Zealand flax fibers (Phormium tenax)", Journal of Reinforced Plastics and Composites, vol.

Fu, Bernd Lauke, and Yiu-Wing Mai, “Science and Engineering of Short Fiber Reinforced Polymer Composites.” Woodhead Limited, 2009. Elias, “Biocomposites: Technology, Environmental References, and Market Forces,” Journal of the Science of Food and Agriculture, vol. Zong, “Evaluating the Relationship Between Water Absorption and Durability of Concrete Materials,” Advances in Materials Science and Engineering, vol.

Tabassi, "Effects of Polymer Modification on the Permeability of Cement Mortars at Different Curing Conditions: A Correlation Study Involving Pore Distribution, Water Absorption, and Compressive Strength," Building and Construction Materials, vol. Cabrera, “Effects of initial setting state on fluid transport properties in OPC and fly ash admixed cement concrete,” Cement and Concrete Composites, vol. Tasdemir, "Combined Effects of Mineral Additives and Curing Conditions on the Sorptive Coefficient of Concrete," Cement and Concrete Research, vol.

Susilorini et al, “The Advantage of Natural Polymer Modified Seaweed Mortar: Green Building Material Innovation for Sustainable Concrete,” Procedia Engineering, vol. 34;Application of response surface methodology in extraction of bioactive component from palm leaves (Elaeis guineensis)," International Journal of Science and Engineering, vol.