Unfired Clay-Cork Granules Bricks Reinforced with Natural Stabilizers: Thermomechanical Characteristics Assessment

Cork is an ecological, natural, and renewable additive, an excellent thermal and acoustic insulator. All these attributes encourage its use in the building sector. Adding this additive to the Earth leads to a more lightweight composite with better thermal performance than the Earth alone. Unfortunately, the mechanical performance of this composite is degraded significantly, limiting its use in construction applications. The authors propose in this study to stabilize the clay-cork composite using natural stabilizers. A chemical stabilization was tested using local quick-lime, in addition to a physical stabilization using natural sheep-wool fibers. The primary purpose is to propose eco-friendly construction material with enhanced thermal and mechanical properties and the lowest environmental impact based on local and ecological raw materials to encourage more sustainable and low-energy constructions. First, physicochemical and mineralogical characterization of used clay was investigated. Then, an experimental investigation was conducted to identify the lime content that allows the optimal stabilization for the used clay. In this context, many different specimens of Bensmim soil stabilized with lime at six many contents 0, 10, 20, 30, 40, 50, and 70% were prepared and tested. The obtained results showed that the optimal lime content for the better stabilization of the used soil is about 30%. Next, an experimental study of thermomechanical properties was conducted on unfired clay bricks mixed with expended cork granules and stabilized by the addition of variable proportions of quick-lime 0, 10 and 30% and sheep-wool fibers 0, 1, and 2%. The mechanical performance of the specimens was investigated in terms of compressive and flexural strengths. At the same time, thermal quality was qualified through evaluating thermal conductivity using the steady-state Asymmetrical Hot Plate test method. The very encouraging experimental findings showed that using lime and sheep-wool fibers at the studied addition content resulted in lightweight composites with lower thermal conductivity and higher compressive and flexural strength than reference samples. The highest thermomechanical performances are obtained with clay-cork blocks reinforced with 30% lime content and 2% sheep-wool fibers. This block recorded values of 583 kg/m3, 0.155 W/m/K, 1.55 MPa, and 3.91 MPa, for bulk density, thermal conductivity, flexural and compressive strength respectively, compared to 765 kg/m3, 0.238 W/m/K, 0.96 MPa and 2.29 MPa for control samples. New material presents lightweight material for both improved thermal and mechanical qualities encouraging its use in building applications. Doi: 10.28991/cej-2021-03091778 Full Text: PDF

Synthesis of Sustainable and High Purity of Quicklime Derived from Calcination of Eggshell Waste in a Laboratory-Scale Rotary Furnace

Quick lime or calcium oxide has attracted significant attention as a sustainable material to be used as fillers and catalysts in a broad range of industries. The quick lime derived from calcination of eggshell waste in a laboratory-scale rotary furnace is reported in this study. The eggshell waste was prepared by washing several times, drying in the sun, grinding and sieving through a 250 micrometers sieve size. Calcination of the sieved eggshells waste was conducted in a single zone rotary tube furnace at 800 °C with 5 degree slope and at 1 rpm. Both physical and chemical properties of the calcium oxide derived from the calcination of eggshell waste were systematically investigated by various scientific instruments. The results from powder X-Ray Diffraction (PXRD) and X-Ray Fluorescence: (XRF) showed that most of the calcium carbonate in the eggshell waste was thermally transformed to nano-calcium oxide with mean crystallite size of 47.5 nm and with a purity of 97.8%. The results from this study indicated the optimum conditions and the possibility for mass production of nano-calcium oxide via rotary furnace and have shown that the obtained nano-calcium oxide is comparable to the commercial chemical.

The Improvement of Engineering Properties of Expansive Soil using Waste Glass Powder (WGP) and Quick Lime

This study was carried out with an intention to observe any sign of improvement of expansive clayey soil due to the addition of Waste Glass Powder (WGP) with it. In this laboratory work clayey (BC) type soil has been chosen. The reason behind choosing clay is that it has many problems. The main problem is that it undergoes consolidation settlement due to the application of long-term loading. Another problem is it shrinks significantly if it is dried and expands significantly, if it absorbs moisture than exerts much pressure on the substructure. Quick Lime and Waste Glass powder is chosen to check the improvement because waste glass powder is cohesionless material and also contains silica, lime etc. Addition of cohesionless material to the cohesive soil means it will lesser the consolidation settlement and expansive nature of soil and Lime provides binding property. To investigate the traditional methods of analysing, the effect of additives on soil has been adopted i.e., conducting several tests of untreated soil and soil treated with waste glass and lime with varying percentage and then comparing the results obtained. The tests that were carried out in this study are Compaction test (Proctor test), Consolidation test (unconfined compression test). MDD and Unconfined compressive strength increases with the addition of glass powder and lime with oven dried expansive soil.

PENGARUH PENAMBAHAN KAPUR TOHOR TERHADAP SIFAT MEKANIS BATA RINGAN

<p align="center"><strong>Abstract</strong></p><p>Light brick is an alternative material in the construction sector that has an efficiency value, in addition to being lighter than conventional bricks for building loads, lightweight bricks also reduce the use of materials during construction. One of the uses of light bricks is on walls. This is because the walls contribute to the heavy load on the building structure. Along with the development of the use of light bricks, research was carried out on light bricks with quick lime mixture as a substitute for part of the cement on light bricks which refers to the mechanical properties of light bricks which include free compressive strength testing, while the variation of the mixture used is 5%, 10%, 15%, and 20% of the volume of cement used. The results of the compressive strength of light bricks at the age of 28 days, respectively, the variation of the lime mixture 5%, 10%, 15%, and 20% obtained compressive strength of 0.96 Mpa, 0.81 Mpa, 0.43 Mpa, and 0.32 Mpa where compressive strength The maximum is obtained in the lime mixture as much as 5%, is 0.96 Mpa.</p><p> </p>

Analisis Kuat Tekan Mortar Geopolimer Berbahan Silica Fume dan Kapur Tohor

ABSTRACT Cement Portland is an essential ingredient in infrastructure development, but in portland cement production, there is a release of carbon dioxide (CO2). Innovation in materials in the construction of mortars, namely geopolymer mortars, is expected to reduce cement and air pollution. The research using experimental methods, aimed at locating the effect of the use of silica fume and quick lime with variations of silica fume: quick lime 90:10, 80:20, 70:30, 60:40, 50:50, using a cube mold of 5 x 5 x 5 cm as much as 120 items, for testing age 7, 14, 28 days. Research has a compressive strength with an optimum geopolymer mortar on a variation of silica fume: quick lime 70:30, which is 3.52 MPa at the age of 28. Based upon compressive strength results, apply the age of mortar 7, 14, 28 days known the longer a strong mortar age agency. Silica fume and quick lime may be used as alternative materials to replace cement. Based on ASTM C 270 to imply mortars type K and type O. ABSTRAKSemen portland merupakan bahan material penting dalam pembangunan khususnya di bidang teknik sipil, namun dalam proses produksi semen portland terjadi pelepasan karbon dioksida (CO2). Perlu adanya inovasi bahan dalam pembuatan mortar yaitu mortar geopolimer yang diharapkan dapat mengurangi penggunaan semen dan polusi udara. Penelitian ini menggunakan metode eksperimental, bertujuan mengetahui pengaruh penggunaan silica fume dan kapur tohor terhadap mortar geopolimer dengan variasi silica fume:kapur tohor 90:10, 80:20, 70:30, 60:40, 50:50, benda uji berbentuk kubus berukuran 5 x 5 x 5 cm sebanyak 120 benda uji, pengujian umur 7, 14, 28 hari. Hasil penelitian didapat kuat tekan optimum mortar geopolimer pada variasi silica fume:kapur tohor 70:30 yaitu 3,52 MPa pada umur 28 hari. Berdasarkan hasil kuat tekan pengaruh umur mortar 7, 14, 28 hari diketahui semakin lama umur mortar kuat tekan semakin meningkat. Silica fume dan kapur tohor dapat digunakan sebagai bahan alternatif pengganti semen. Berdasarkan ASTM C 270 termasuk dalam mortar tipe K dan tipe O.

Effect of Pozzolana and Lime on Expansive Soil Properties

This study investigates the effect of pozzolana and quick lime as stabilizer materials on expansive soil properties. Disturbed soil sample was collected from Al-Qadarif city in east of Sudan. The basic properties, swelling and strength of the soil were measured. The soil shows very weak strength and very high swelling potential. Mineralogical analysis tests were conducted to the soil using XRD tests. The soil contains significant amount of montmorillonite mineral (86%). Laboratory tests were undertaken on soil stabilized with varying percentage of pozzolana only (0, 5, 10, 15, 20, and 30%) and combination of pozzolana with constant content of quick lime (5%). Compaction, California Bearing Ratio (CBR), free swell, swell present and swelling pressure tests were performed on natural and treated soil. The pozzolana was obtained from Jebal Meidob and the lime obtained from local kilns in Kassala. The results showed that the treatment of expansive soil by combination of pozzolana and quick lime reduced soil swelling coupled with significant increase on soil strength. While the use of pozzolana only has marginal effective. It could be concluded that stabilization of expansive soil by pozzolana-lime admixture is successful.

Three-Dimensional Printing of Natural Materials Involving Loess-Based Composite Materials Designed for Ecofriendly Applications

In this work, loess-based materials were designed based on a multicomponent composite materials system for ecofriendly natural three-dimensional (3D) printing involving quick lime, gypsum, and water. The 3D printing process was monitored as a function of gypsum content; in terms of mechanical strength and electrical resistance, in the cube-shaped bulk form. After initial optimization, the 3D printing composition was refined to provide improved printability in a 3D printing system. The optimal 3D fabrication allowed for reproducible printing of rectangular columns and cubes. The development of 3D printing materials was scrutinized using a multitude of physicochemical probing tools, including X-ray diffraction for phase identification, impedance spectroscopy to monitor setting behaviors, and mercury intrusion porosimetry to extract the pore structure of loess-based composite materials. Additionally, the setting behavior in the loess-based composite materials was analyzed by investigating the formation of gypsum hydrates induced by chemical reaction between quick lime and water. This setting reaction provides reasonable mechanical strength that is sufficient to print loess-based pastes via 3D printing. Such mechanical strength allows utilization of robotic 3D printing applications that can be used to fabricate ecofriendly structures.