Physical and Chemical Characterization of Coffee Husk Ash Effect on Partial Replacement of Cement in Concrete Production

Abstract

Today researchers all over the world are focusing on ways of utilizing either industrial or agricultural wastes as a source of raw materials for the construction industry. This is used to minimize the emission of CO2 during the manufacturing of cement. One of the agricultural waste products is coffee husk which is found in large amounts in Ethiopia. This paper aims to characterize the physical and chemical properties of Coffee Husks Ash (CHA) by using X-ray diffraction (XRD), Scanning electron microscope (SEM), and Fourier Transforms Infrared Spectroscopy (FTIR) tests, and also the experiment were conducted to determine the compressive, split tensile and flexural strength of the material and durability tests were determined. The result have shown that, when the replacement percent further increases, the crystalline material increases, silicate concentration decreases, and also the micro pores or air void are increases, which may lead to decreasing the strength of concrete. In the case of mechanical property of concrete, there has been remarkable increment up to 5% CHA replacement and also strongly satisfied up to 10% replacement, furthermore increasing CHA replacement up to 20% are optimum dosage of normal concrete mix production of C-25 concrete. Finally, water absorption and sulfate attack of partially replaced concrete is shown as an improvement in the durability of concrete.

Development Of Eco-Friendly Concrete: Research On The Use Of Coffee Husk Ash As A Sustainable Alternative

“…Figure 3 shows changes when the percentage of partial substitution and addition varies. In the case of ACHA, it is noted that the workability of the concrete decreases with a higher percentage of partial substitution, coinciding with previous studies that report a reduction in the slump with more presence of CHA [5], [10]; [12]; [29]. Concrete with CHA requires more water due to the absorbent nature and high fineness of CHA's cellular particles [29].…”

“…The procedure described by [5] was followed, which initially involves sun-drying the sample to remove surface moisture (Figure 1(a)). The sample was then oven-dried at 600°C for 4 hours to obtain Coffee Husk Ash (CHA) with a dark gray color.…”

“…The concrete mix for (𝑓𝑓 𝑐𝑐 ′ = 26 𝑀𝑀𝑀𝑀𝑀𝑀) was directed with ACI using characterized results of the aggregates. It was proposed to substitute 2%, 4%, 6%, 8%, and 10% of OPC with CHA based on the results of [5]. Following the same substitution percentages with CHA, Banana Stem Sap (BSS) was added to increase strength without significantly affecting the water/cement ratio.…”

“…The simple compression variable of both standard concrete and experimental mixtures was evaluated following standard NTE INEN 1573, using the Shimadzu Concrete 2000x equipment. Testing was conducted at curing ages of 7, 21, and 28 days, and substitution levels (2%, 4%, 6%, 8%, and 10%) of OPC with CHA were based on the findings of [5]. Banana Stem Sap (BSS) was added to increase strength without significantly affecting the water/cement ratio.…”

“…Partial substitution of OPC with sustainable materials up to 30% demonstrates new concretes that meet national and international requirements [14]. Innovating new sustainable materials in concrete mixtures leads to new eco-friendly concrete [5]. Agricultural solid waste constitutes a significant portion of total waste in our society [24].…”