scholarly journals Carbon Dioxide: A Raw Material for Cementitious Mortar

2021 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Alessandro P. Fantilli ◽  
Riccardo Calvi ◽  
Edoardo Quieti ◽  
Pier Luigi Radavelli

Buildings and infrastructures can absorb CO2 from the atmosphere because of the carbonation process that affects the calcium hydroxide of concrete elements. The aim of this research project is to initiate the absorption at casting by adding dry ice pellets to cement-based mortars. Test results demonstrate that the flexural and compressive strength of the mortars are not modified by this addition. Conversely, due to the presence of CO2, the standard deviation of strength reduces with respect to that measured in plain mortars. Thus, carbon dioxide can be considered a valuable resource that improves the mechanical behavior of construction materials.

2016 ◽  
Vol 690 ◽  
pp. 109-113 ◽  
Author(s):  
Sutthima Sriprasertsuk ◽  
Phatthiya Suwannason ◽  
Wanna T. Saengchantara

This work investigated the recycling of fly ash waste and cullet as the raw materials for lightweight bodies produced by heat treatment and using sodium silicate as the binder. Borax was mixed with fly ash and cullet, and put into the block in dimension 10x10x2 cm3. The lightweight materials thus produced were then sintered at temperature of 800 °C. Density, compressive strength and thermal conductivity were determined. Borax showed a positive sintering effect on the porosity of lightweight material during the heat process. The compressive strength of lightweight material diminished with the reduction of density and thermal conductivity. Lightweight material manufactured with borax showed the lower density and thermal conductivity accompanied by the higher compressive strength. The test results indicated that using fly ash and cullet as the raw material with borax could obtain the lightweight material, thus enhancing the possibility of its reuse in a sustainable way.


2019 ◽  
pp. 205-214
Author(s):  
Ikumapayi C. M. ◽  
Adeniji A. A. ◽  
Obisesan A. A. ◽  
Odeyemi O. ◽  
Ajayi J. A.

Concrete is one of the reliable, durable, economical and acceptable construction materials among the building and construction stakeholders worldwide. Performance of concrete could be threatened especially reinforced concrete by some processes such as corrosion, sulfate attack among others. Corrosion of reinforcement in reinforced concrete can be induced by carbonation process. Even though carbonation initiates corrosion, it has been gathered that carbonation could still be of immense benefits to building and construction industries if its mechanism of operation is understudied. This research work has therefore investigated the effect of carbonation on some selected mechanical properties of concrete such as compressive strength, flexural strength, water absorption and weight changes. Concrete cubes and beams of M15 grade with 0.5 % water-cement ratio were prepared and subjected to accelerated carbonation. Their compressive strength, flexural strength, water absorption and weight changes were determined in accordance with the relevant standards. The outcomes show that carbonation improves all the mechanical properties investigated. The use of carbonation can be positively explored in reinforced concrete provided there is adequate nominal cover.


2017 ◽  
Vol 10 (3) ◽  
pp. 744-759
Author(s):  
G. O. RIBEIRO ◽  
P. C. GUETTI ◽  
P. SERNA

ABSTRACT Considering the physical nonlinearity of concrete and the fundamentals of fracture mechanics for quasi-brittle materials, the objective of this study was to determine the fracture energy and the length of the fracture process zone (FPZ) as well as the modulus of elasticity, the tensile strength and the compressive strength of self-compacting concrete (SCC) to characterize its mechanical behavior. A series of tests, including a three-point bending test of SCC and conventional vibrated concrete (CVC) specimens, with a notch at mid-span, and tensile and compressive tests were performed. The mechanical parameters obtained from the CVC specimens were considered as a comparative reference. The effect of the following variables was evaluated and considered at two levels: compressive strength (30 and 50 MPa), granular composition (fine and coarse particle size) and maximum diameter of the aggregate (12 and 20 mm). The effect of these variables on the mechanical behaviors of the SCC specimens was evaluated based on the test results of specimens of four types of concrete, which were obtained from the combination of the variables. The bending tests were performed according to the RILEM TC 89-FMT recommendations, which are based on the size-effect method.


2017 ◽  
Vol 259 ◽  
pp. 106-110
Author(s):  
Elżbieta Szczygielska ◽  
Viktar V. Tur

A new conformity criterion for concrete strength assessment that could be used at the initial production stage, is proposed. As an innovative conformity criterion was evaluated based on Order Statistics Theory, it is independent from the type probability density function (PDF) in population, estimation of the standard deviation, shape of the specimen and the level of autocorrelation of the test results. Proposed criterion was evaluated and positively verified both AOQL-concept using Monte Carlo simulation and the test results obtained under real production.


2011 ◽  
Vol 374-377 ◽  
pp. 1303-1306
Author(s):  
Qing Bo Tian ◽  
Li Na Xu ◽  
Li Yang ◽  
Xiu Hui Wang ◽  
Hong Gao

A concrete paving blocks was produced using pretreated concrete wastes as main raw material by pressure forming and steam-curing at 70°C. The test results showed that with the increase of water addition, the paving blocks increase its strength. And as the additions of water amount reach to a critical value, the compressive strength has an adverse change and decreased. As the rise of ratio of cement and wastes, the compressive strength also increases. The difference in various ratios of cement and wastes is that the difference of water needed as the compressive strength achieved its highest value. The thermal treatment temperatures has greatly influence on the compressive strength. The increments of thermal-treated temperatures induce the active material to form and cause the particle grading more reasonable in the concrete wastes, which is benefit to the shaping of specimen and increasing of strength. The maximum compressive strength of 53.2 MPa is obtained in the mixture thermal-treated at 800°C by adjusting the water additions.


2020 ◽  
Vol 29 ◽  
pp. 2633366X2096250
Author(s):  
Masturi ◽  
WN Jannah ◽  
RM Maulana ◽  
T Darsono ◽  
Sunarno ◽  
...  

A teak leaf waste/polyurethane composite has been made for particleboard application. Some fraction variations are performed on the use of polyurethane as a matrix with a range of 0.04–0.20 (w/w). Mechanical and physical properties have been tested on the composites produced. The test results showed that the highest compressive strength of the sample reaches 38.5 MPa for polyurethane fraction of 0.14 (w/w). The composite has a density of 1261 kg m−3 which is in accordance with the result of density on teak. The physical properties have been also investigated and it was found that the lowest value of water absorption is 1.38%. This result indicated that the composites produced are potentially to replace wood raw material in eco-friendly industrial scale.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5671
Author(s):  
Jacek Szpetulski ◽  
Bohdan Stawiski

During compaction of a concrete mix, when thin slabs are formed in a horizontal position, the components of this mix become segregated. Heavy components fall to the bottom, and light components (air and water) move to the top. This process may suggest that the upper layers of concrete elements formed in a horizontal position may have lower compressive strength than the remaining part of the element. This problem is recognized and documented in many publications, but there was a publication whose test results indicate a lack of variability in the compressive strength of concrete across the thickness of tested elements. The discrepancies appearing in the evaluation of concrete homogeneity was the reason for conducting destructive tests of the compressive strength of concrete across the thickness of horizontally concreted test elements that imitate thin slabs. The obtained results of the destructive compressive strength confirmed previous results regarding the heterogeneity of concrete. They clearly indicate that there is a differentiation of the compressive strength of concrete across the thickness of a thin element, which remained in a liquefied state for a certain time during its formation. The longer the duration of this state across the entire thickness of the formed element, the greater the differentiation of the compressive strength between the top and bottom layers.


2019 ◽  
Vol 1 (3) ◽  
pp. 211-218
Author(s):  
Desi Putri ◽  
Rr. Mekar Ageng Kinasti ◽  
Divad Fredonanta Lalus

AbstractIncreased housing construction has resulted in an increased demand for concrete beams, this of course has an impact on the needs of basic materials such as sand. The increasing demand for sand will have an impact on the price of sand, especially for areas that are difficult to get sand as raw material. An alternative to sand is to use basic ash. This waste will accumulate and pollute the environment. One effort to reduce this waste was to make glass waste as a substitute for cement in bricks. This study aimed at determining the compressive strength of concrete beams using bottom ash and cement with glass waste in a certain percentage. This research was carried out in two testing stages. In the initial stage of the study, the preliminary phase carried out included the physical properties of the material testing. The second step was to make test specimens with four variations of the mixture, that was 0%, 10 % LK + 10 % BA, 10 % LK + 20 % BA dan 10% LK + 30 % BA, and then a compression test on 7, 14 and 28 days of age. From the test results, the compressive strength results obtained from the brick using bottom ash and glass waste were respectively 4,13 MPa, 4,31 MPa, 7,14 MPa dan 5,21 Mpa. Based on the results of the research (no subject of the sentence) we concluded that the most increased compressive strength of the brick was on 10 % LK + 20 % BA variation, and the decrease of compressive strength started on 10 % LK + 30 % BA variation.Keywords : brick, residential, bottom ash, compressive strength, glass waste.AbstrakMeningkatnya pembangunan hunian mengakibatkan naiknya permintaan akan batako, hal ini tentunya berdampak terhadap kebutuhan bahan dasar batako seperti pasir juga mengalami peningkatan. Kebutuhan pasir yang meningkat akan menaikkan harga pasir, terutama untuk daerah yang sulit mendapatkan bahan baku pasir. Bahan alternatif pengganti bahan baku pasir salah satunya adalah dengan memanfaatkan limbah bottom ash. Selama ini limbah bottom ash hanya ditimbun di lahan kosong, sehingga menumpuk. Hal ini tentunya sangat berbahaya apabila bottom ash terbawa angin atau air karena dapat mencemari lingkungan serta mengganggu pernapasan. Limbah kaca merupakan salah satu limbah anorganik hingga saat ini. Limbah ini dibuang begitu saja tanpa adanya pengolahan yang lebih bermanfaat sehingga menumpuk dan terkesan hanya mengotori lingkungan sekitarnya. Salah satu upaya mengurangi limbah ini dengan menjadikan limbah kaca sebagai substitusi semen pada batako. Penelitian ini bertujuan untuk mengetahui kekuatan tekan batako bila pasirnya digantikan dengan limbah bottom ash dan semen digantikan dengan limbah kaca menggunakan prosentase tertentu. Penelitian dilakukan secara eksperimental di laboratorium dengan dua tahap pengujian. Pada tahap awal penelitian dilakukan pengujian pendahuluan meliputi pengujian sifat fisik bahan. Tahap kedua dilakukan pembuatan benda uji dengan dengan empat variasi campuran yaitu 0%, 10 % LK + 10 % BA, 10 % LK + 20 % BA dan 10% LK + 30 % BA kemudian dilakukan uji tekan pada umur 7, 14 dan 28 hari. Dari hasil pengujian, didapat hasil kuat tekan batako menggunakan limbah bottom ash dan limbah kaca masing-masing adalah 4,13 MPa, 4,31 MPa, 7,14 MPa dan 5,21 MPa. Berdasarkan hasil penelitian dapat disimpulkan bahwa kenaikan kuat tekan terbesar batako terdapat pada variasi 10 % LK + 20 % BA  dan terjadi penurunan kuat tekan batako pada variasi 10 % LK + 30 % BA.Kata kunci  : Batako, hunian, bottom ash, kuat tekan, limbah kaca. 


2019 ◽  
Vol 974 ◽  
pp. 224-230 ◽  
Author(s):  
Ekaterina Victorovna Fomina ◽  
Valery S. Lesovik ◽  
M.I. Kozhukhova ◽  
Elena B. Solovyova

Nowadays, in order to design durable construction materials all collected knowledge on material science as well as modern technologies allow solving the problems by applying mimicry or nature-like are technologies based on interdisciplinary study of geonics. Considering the principles of geology, it is important to study the influence of genetic characteristics of raw materials on structural performance and durability of final construction materials. The following paper focuses on assessment of effect of genetic characteristics of industrial by-products such as materials derived from iron-ore production at the Kursk Magnetic Anomaly on carbonation resistance in autoclave cellular concrete was studied. The secondary products of ore rigging process, the screening fraction of sandstone, shale rocks as well as tailings of wet magnetic separation were used as a quartz-bearing mineral components. The evaluaton parameters in this study were compressive strength, density and carbonation resistance of autoclave cellular concrete (ACC) specimens. The carbonation process was reproduced in laboratory prepared concrete. In order to eccelerate carbonation reaction all specimens were stored in a sealed chamber saturated with CO2. The density and compressive strength characteristics of ACC with regular quartz sand were 630 kg/m3 and 3.6 МPа, respectively. The same parameters were slightly higher in case of full replacement of quartz sand by sand stone and demonstrated 655 kg/m3 and 3.9 МPа, respectively, and carbonation resistance was increased by 20 %. The results support the view, that screening fraction of sandstone that had been formed under natural metamorphosis is more preferable for use in ACC production. Full replacement of regular quartz sand by sand stone in ACC specimens showed improved compressive strength and carbonation resistance.


2015 ◽  
Vol 744-746 ◽  
pp. 617-620
Author(s):  
Kai Xi An ◽  
Yi Xiang Chen ◽  
Ruo Qi Lou ◽  
Min Jiong Wu

In order to reveal the effect of admixture type and quantity on the strength of stabilized soil, a series of indoor test is done on the stabilized soil by means of unconfined compressive strength test. The raw material soil used in the experiment is sludge soil, and cement, triethanolamine, caustic soda are used as admixture. A lot of solidified samples are prepared according to test scheme in different admixture’s proportion. From the test results, it can be seen that different admixture and it’s quantity affect the strength of stabilized soil by analyzing the sample’s unconfined compressive strength test results.


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