scholarly journals Characterization of Slag Cement Mortar Containing Nonthermally Treated Dried Red Mud

2019 ◽  
Vol 9 (12) ◽  
pp. 2510 ◽  
Author(s):  
Gyeongcheol Choe ◽  
Sukpyo Kang ◽  
Hyeju Kang

In this study, a method was suggested to produce dried powder from red mud (RM) sludge with 40%–60% water content without heating. The RM sludge is discharged from the Bayer process, which is used to produce alumina from bauxite ores. Nonthermally treated RM (NTRM) powder was produced by mixing RM sludge (50%), paper sludge ash (PSA, 35%), and high-calcium fly ash (HCFA, 15%). The physicochemical properties of NTRM were investigated by analyzing its water content, X-ray fluorescence spectra, X-ray diffraction patterns, and particle size. Moreover, to examine the applicability of NTRM as a construction material, slag cement mortar in which 20 wt% of the binder was replaced with NTRM was produced, and the compressive strength, porosity, and water absorption rate of the mortar were evaluated. Results indicated that NTRM of acceptable quality was produced when the water content in RM sludge decreased and CaO contained in PSA and HCFA reacted with moisture and formed portlandite. The NTRM-mixed mortar requires further examination in terms of durability because of the increased capillary voids and high water absorption rate, but its compressive strength is sufficient to enable its use in sidewalks, bike roads, and parking lots.

2021 ◽  
Vol 22 (2) ◽  
pp. 83-97
Author(s):  
Mohd Haziman Wan Ibrahim ◽  
Mohammed Yahya Al-Fasih ◽  
Nik Nadia Amira NIK PA ◽  
Ramadhansyah Putra Jaya ◽  
Muhammad Ikhsan Setiawan

In this study, the properties of mortar such as standard consistency, setting time, compressive strength, and water absorption rate were investigated. The cement was replaced with Pennisetum purpureum ashes (PPA) in different particle sizes and dosages. PPA was produced in greyish-white ash with total reactive oxides ranging from 37% to 41.1%. Pennisetum purpureum grass (PPG) was burned with a controlled process at 350 °C for the first 3 hours and 600 °C for another 3 hours at a heating rate of 10 °C/min. Then, PPG was ground in three different grinding durations (1, 3, and 6 hours) producing ashes with particle sizes of 10.58 µm, 10.25 µm, and 9.30 µm, respectively. The physical, chemical, and microstructural properties of PPA were evaluated through several tests; particle size analysis, X-ray diffraction analysis, loss on ignition, and chemical composition. Results indicated that PPA is more suitable for use as filling material as a substitute for cement than pozzolanic material as its reactive oxides are less than 50%. The 15% 6H-PPA at 28 days was found to be the optimum PPA replacement dosage and grinding time with cement as it achieved the highest strength and lower water absorption rate among all samples at 7 and 28 days. ABSTRAK: Kajian ini berkenaan sifat mortar seperti konsistensi standard, masa penyediaan, kekuatan menyeluruh, dan kadar penyerapan air.  Simen ditukar dengan abu Pennisetum purpureum (PPA) dalam saiz partikel dan sukatan berbeza. PPA pula dihasilkan melalui habuk putih-kekelabuan dengan total reaktif oksida dengan julat purata 37% ke 41.1%. Rumput Pennisetum purpureum (PPG) dibakar dengan proses kawalan pada 350 °C selama 3 jam pertama dan 600 °C pada 3 jam berikutnya pada kadar pemanasan 10 °C/min. Kemudian, PPG dikisar dalam tiga tempoh kisaran berbeza (1, 3, dan 6 jam) menghasilkan abu dengan saiz partikel 10.58 µm, 10.25 µm, dan 9.30 µm, masing-masing. Fizikal, larutan kimia dan sifat struktur mikro PPA telah dikaji melalui pelbagai ujian; analisis saiz partikel, analisis pembelauan X-ray, kehilangan semasa penyalaan dan kandungan kimia. Dapatan kajian menunjukkan PPA adalah lebih sesuai digunakan sebagai material pengisian ganti kepada simen berbanding material pozzolanik kerana reaktif oksida adalah kurang daripada 50%. PPA adalah maksimum pada 15% 6H-PPA selama 28 hari, didapati lebih sesuai sebagai dos pengganti dan masa kisaran bersama simen, kerana kekuatan menyeluruh adalah paling tinggi dan kadar penyerapan air paling kurang antara semua sampel pada 7 dan 28 hari.


Author(s):  
Ovie Isaac AKPOKODJE ◽  
Goodnews Goodman AGBI ◽  
Hilary UGURU

This paper evaluated the influence of cassava effluent on the compressive strength of concrete for farm structures. Three sets of concrete cubes were produced with a concrete mix ratio of 1:2:4 (C 15) and a water to cement ratio (w c-1) of 0.5. The 1st set was produced with 100% fresh water (tap water). The 2nd set was produced with 75% partial replacement of the fresh water with fresh cassava effluent, while the 3rd set was produced with 75% partial replacement of the fresh water with old cassava effluent. The density, water absorption rate and compressive strength of the concrete cubes was tested in accordance with ASTM International standards, at the end of 7, 14, 21, 28 and 56 curing days. The results revealed that, the cassava effluent slightly increased the cubes density; but reduced their water absorption rate. The study further showed that, concrete produced with fresh cassava effluent, developed the highest compressive strength (29.57 MPa) at the end of the 56th curing day. In contrast, concrete produced with old cassava effluent developed the lowest compressive strength (24.43 MPa) at day 56, which was lower than the compressive strength of 27.18 MPa developed by the concrete produced with fresh water (also at day 56). In addition, the cassava effluent retarded the initial rate of strength development, as such, increasing its prospect as an organic concrete admixture. This study will be helpful in mitigating the harmful effects of cassava effluent in the environment, since it can be utilized in concrete production.


2017 ◽  
Vol 889 ◽  
pp. 261-264 ◽  
Author(s):  
Norpadzlihatun Manap ◽  
Nor Izzah Muhamad ◽  
Kavitha Sandirasegaran

Concrete is one of the most important materials for construction industry. The material in the mixture of concrete includes cement, sand and coarse aggregate. Production of cement causes the air pollution from the emission of carbon dioxide to the air. This research studies the replacement of cement with palm oil fuel ash (POFA) in the concrete mixture. The objective of this research is to investigate the compressive strength of concrete and water absorption rate of concrete made from POFA and to compare the strength and absorption rate between conventional concrete and concrete made from POFA. This is to indicate whether the compressive strength and absorption rate are equivalent to the strength of conventional concrete. The methodology used in this research is experimental method and the palm oil fuel ash was taken from palm oil mill in Cha’ah, Johor, Malaysia. The results of this research are the specimens which contain 20% POFA has a compressive strength and water absorption rate comparable to conventional concrete.


2016 ◽  
Vol 857 ◽  
pp. 319-322
Author(s):  
Nur Fitriah Isa ◽  
Khairunnisa Muhammad ◽  
Norhaizura Yahya ◽  
Muhammad Munsif Ahmad ◽  
Mohd Badrul Hisyam Ab Manaf ◽  
...  

Dolomite is a sedimentary rock resulting from the deposition of river or sea takes millions of years. The quarry waste from dolomite production had been used to replace sand in order to study the performance of modified brick sand. The objectives of this research are to determine the density, water absorption rate, and compressive strength of the new dolomite brick (d-brick) and to find out the optimum percentage of sand replacement with the dolomite waste. The bricks sample are then be tested using physical and mechanical approach. The percent of sand replacement is 25%, 50%, 75%, and 100% by weight.The optimum percentage mix of the modified sand brick using dolomite is D50 based on the density, water absorption, and compressive strength test of the sand brick. The result of the density of the D50 sand brick using dolomite is 1701 kg/m3, the water absorption of the sand brick 12%, and 14% at 7 days, and 28 days respectively. Meanwhile, the compressive strength of the D50 sand brick is 7.99 MPa, and 12.28 MPa at 7 days, and 28 days.


2013 ◽  
Vol 739 ◽  
pp. 268-271 ◽  
Author(s):  
Jian Quan Li ◽  
Ming Zhu Gong ◽  
Guo Zhong Li

The paper studied a compound desulphurization gypsum waterproof agent, which could modify the water-resistance performance of gypsum products on the basis of their microstructural properties. The waterproof mechanics were the synthesis results of superficial hydrophobic of hydrophobic emulsion, hindrance water of film forming matter and reducing the porosity in materials. The experiment results showed that the water-absorption rate of gypsum hardened body can be reduced to 3.5% and that the compressive strength reserve rate was 89.7% after 24h.


2010 ◽  
Vol 168-170 ◽  
pp. 1680-1685 ◽  
Author(s):  
Zong Ping Chen ◽  
Ni Wang ◽  
Shi Qian Zhang ◽  
Shu Fang Zheng

In order to study the mechanical behavior of recycled fine aggregate mortar, 11 kinds of different recycled fine aggregate replacement rate (ranged from 0% to 100%, level differential 10%) of cement mortar test specimens are designed. The failure pattern and the mechanical performance indexes of the cement mortar under different recycled fine aggregate replacement rate are gained by test. And the different physical indexes of natural fine aggregate and recycled fine aggregate are measured in detail. The experiment findings indicate that because the water absorption rate of the mortar with high porosity is higher, and there are mass microcracks in recycled fine aggregate interior due to damage accumulation, the lower apparent density, the higher water absorption rate and the quicker water absorption speed of recycled fine aggregate are caused. So the fluidity of recycled fine aggregate mortar is fine, but the water retention is bad, the compressive strength is lower than the natural fine aggregate mortar about 50%. But the replacement rate has little effect on the mortar strength.


Portland cement is a kind of cement used where the high strength and durability is needed. Also, this type of cement is essentially used to control the CO2 emission during the manufacturing process of the concrete. This cement is made up of slag with the activator such as alkalis in the form of sodium hydroxide or sodium silicate. However, this addition is increasing the overall cost of the production of concrete. In this research, a new attempt has been made to use the natural activators of Rice Husk Ash (RHA) and Natural Steatite Powder (NSP). This research aims to determine the effects of RHA and NSP with Portland slag cement by partial replacement with 5%, 10%, 15% and 20% of RHA and NSP. The influence of the RHA and NSP on the mechanical properties of the mortar was evaluated by measuring the compressive strength and the split tensile strength. The durability properties of the specimens were analyzed by water absorption, sorpitivity and acid attack tests. The analysis of the microstructure of the specimens was done by scanning electron microscope (SEM) and Fourier Transform Infrared Spectra analysis (FTIR). It was observed that the maximum compressive strength and split tensile strength was in 5% RHA and NSP blended mortar. The durability results showed that the 10% RHA and 10% NSP had lesser water absorption and sorpitivity values. From the results of micro structural analysis it was observed that replacing cement with 5% RHA and 5% NSP results in improvement of microstructure of cement mortar.


Author(s):  
Saleh Bamaga

Abstract This paper presents the results of a study conducted to investigate the effects of incorporating Sefri Date Palm Leave Fibers (SDPLF) into the mortar. A total of seven mixtures were prepared and tested. SDPLF were collected from local farms. The fibers were then cleaned, dried, and cut to different sizes of 10 mm, 20 mm, and 50 mm, maintaining the same individual fiber width of approximately 5±2 mm. The content of SDPLF in mortars was kept to 1% and 3% by mass. The physical and mechanical properties of SDPLF fibers and SDPLF mortars were investigated. The compressive strength at 7, 14, and 28 days was determined. The water absorption rate test was carried out on mortars containing 1% SDPLF fibers. The results showed that mortars with SDPLF have lower workability, lower density, and lower compressive strength as compared to control mortars. However, they are still acceptable for use in construction works. Mortars containing 10 mm and 20 mm SDPLF fibers by mass showed significant improvement in terms of water absorption rate as compared to the control mortar.


2011 ◽  
Vol 239-242 ◽  
pp. 600-603
Author(s):  
Jian Quan Li ◽  
Ming Zhu Gong ◽  
Guo Zhong Li

A novel compound gypsum waterproof agent made of emulsified stearic acid, alunite and naphthalene were studied, which could modify the waterproof performance of gypsum materials in microstructures. The experiment results showed that the water-absorption rate of gypsum materials can be reduced to 3.73% and that the compressive strength reserve rate was 84.71% after 24h. The waterproof mechanic of alunite is the hydration materials of alunite can fill the materials’ porosities, which can no longer be filled with water, so it reduces the water absorption and improves the strength; The waterproof mechanic of stearic acid emulsion is that it improves the gypsum material surface performance and makes the surface performance convent from hydrophilic performance to hydrophobic performance.


2012 ◽  
Vol 174-177 ◽  
pp. 1306-1311
Author(s):  
Jun Liu ◽  
Jin Hu Shi ◽  
Fang Zhi Lin ◽  
Wen Hui Sun

Objective:this paper would research the effects of different dosages of admixtures doped to the adobe wall materials' compressive strength, 30min soaking compressive strength loss rate, water resistance, water absorption rate and resistance drying and watering cycle can be modified by cement, stone powder and fly ash three admixtures which are single-doped into the samples. Result: The single-doped cement can enhance the durability of the adobe wall materials obviously. When the dosage of stone powder's single-doped is 0~5%, it can lower the 30min soaking compressive strength loss rate and water absorption rate. When the dosage of it's single-doped is 5~15%,it raises the 30min soaking compressive strength loss rate and water absorption rate. While the dosage of single-doped fly ash is increasing, it could lower the adobe wall materials' compressive strength, but other performance lowers after that first enhances,and the single-doped dosage of 5% is the turning point performance.Conclusion: Three kind of admixtures can modify the adobe wall materials' durability. When the dosage of stone powder and fly ash's single-doped are 5%,the sample's performance of water resistance is best.It meets the demands of the adobe wall materials' durability.


Sign in / Sign up

Export Citation Format

Share Document