Rapid Prototyping of Full Scale House Structures

Author(s):  
Sangju Lee ◽  
Eberhard Bamberg ◽  
Charles Eason

This paper reports on the machining of a construction material (aerated concrete) with a rapid prototyping device, Shapemaker III, which is based on waterjet technology. Preliminary machining tests were carried out to investigate machining conditions (speed and pressure) of separation cuts. Cutting speeds for the waterjet were investigated for two aerated concrete construction materials; autoclaved aerated concrete (AAC) in two strengths (348 and 580 psi compressive strength) and a non-autoclaved, fiber reinforced aerated concrete (FRAC) with a 450 psi compressive strength. Cutting samples were prepared in four thicknesses (0.5, 1, 2, and 3 inches) and cut at two pressures (40 and 60 ksi). The 0.5 and 1 inch specimens were cut with good surface finish at over 600 in/min at 40 ksi. The 2 and 3 inch specimens could be cut at 320 and 80 in/min at 40 ksi, respectively. The experimental data was used in the fabrication of rapid prototyping houses with a pure waterjet machine. As results, full scale houses were fabricated with FRAC and Styrofoam. Additionally, a sub-mold of an outdoor fireplace was manufactured with Styrofoam for casting of customized aerated concrete blocks.

2012 ◽  
Vol 174-177 ◽  
pp. 1253-1256
Author(s):  
Li Peng Cai

In this paper, thermal insulating bonding mortar has been produced by the spent polystyrene foam particles, cement, sand, tackifier and water etc. It shows that thermal insulation performance and compressive strength of thermal insulating bonding mortar are similar with those of aerated concrete by comparison tests. In this paper, the new wall is made by thermal insulating bonding mortar and aerated concrete blocks, and the results show the thermal insulating performance of this wall can be improved and its cold bridge impact can be eliminated too. Correspondingly, the energy saving effect of buildings can be improved rapidly.


2018 ◽  
Vol 15 (1) ◽  
pp. 47
Author(s):  
NURUL NAZIERAH MOHD YUSRI ◽  
KARTINI KAMARUDDIN ◽  
HAMIDAH MOHD SAMAN ◽  
NURAINI TUTUR

Sewage sludge is a by-product generated within the wastewater treatment process. Severe concern arised as the sludge are massively been dumped to the landfill and it may affect the environment. Many studies had been conducted in reusing the sewage sludge as construction material, where it is one of the optional ways to solve the issue. In this study, dried sewage sludge was incinerated with two different temperatures in order to produce sewage sludge ash (SSA), which are 800°C and 1000°C. After few processes, this SSA then reused in mortar as cement replacement with the replacement percentage of 5%, 10%, 15% and 20% by weight. The strength performance of mortar specimens was investigated after 7, 28, 60 and 90 days of curing. From the results, it is clearly showed that the compressive strength of all mortar specimens increased when the period of curing was prolonged. Moreover, almost all compressive strength of SSA mortars was higher than the control mortar. Therefore, there is potential to reuse this waste material as part of construction materials and hence, its plays an important role for future researches in minimisation of waste.


2019 ◽  
Vol 974 ◽  
pp. 665-671
Author(s):  
Omar Ismael Alhashimi ◽  
AL-Hasnawi Yasser Sami Ghareb

Many of the complex reinforced Autoclaved Aerated Concrete characteristics under shear and flexure are yet to be identified to employ this material advantageously and economically, as it has many advantages of low weight, fire resistance, acoustic and thermal insulation. It is observed in the article that under two-points loading system, diagonal cracks are usually the first cracks to be observed in the deep beam clear span. The diagonal cracks first are developed in relatively deep beams and the flexural cracks are first developed in shallower beam. The principal mode of failure in the deep beams having adequate reinforcement is diagonal tension cracking. The shear failure is a common type for all beams. This indicates a weak the bond strength between lightweight concrete and reinforcing steel. There are many factors affecting the bond strength between the lightweight concrete and reinforcing steel, where the compressive strength plays an important role in bond strength, and the bond strength is increased by increasing the compressive strength. The AAC beams have the potential to be an excellently energy-saving construction material and is believed to emerge as an alternative to traditional reinforced concrete beam in the near future. This is proved by the experimental analysis.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2641
Author(s):  
Sukpyo Kang ◽  
Hyeju Kang ◽  
Byoungky Lee

An increasing amount of red mud (RM) is being generated globally due to the growth in aluminum production. To avoid RM pollution, low-cost methods for effectively recycling RM are being investigated. We propose a method for recycling RM as a construction material. Liquefied RM (LRM) was neutralized by nitric acid and added to cement paste, and the hydration heat, compressive strength, and hydration products were investigated. The cement paste with neutralized LRM had a higher compressive strength than that of plain cement paste and cement paste with LRM without neutralization at 1 day of aging; this indicates that nitric acid neutralization increases the early-age strength. Furthermore, the cement paste with 10% neutralized LRM showed 28 days-compressive strength and hydration heating curves similar to the plain mixture, indicating the positive impact of LRM neutralization on the strength. It was noted that a greater quantity of portlandite was produced earlier in cement paste with neutralized LRM than in that without. Therefore, the proposed method of using RM as a concrete additive has the potential to reduce the cost and environmental impact of both construction materials and RM waste management.


2020 ◽  
Vol 8 (6) ◽  
pp. 3508-3513

Autoclaved aerated concrete (AAC) blocks are the lightweight and green concrete blocks that are composed of cement, fly ash, lime, gypsum and aluminium powder. Depending on its density AAC consists of up to 80% of air by volume. Due to their low density and lightweight Autoclaved aerated concrete blocks exhibit so many favourable physical properties that these have got attention from all around the globe. Due to these enhanced properties Autoclaved aerated concrete blocks are extensively used as masonry units in all types of construction. On one hand AAC blocks have no comparison with other types of masonry units in terms of physical properties but on other hand AAC blocks are found to have low compressive strength relatively. In this study an attempt has been made to study the influence of Alkali-Resistant Glass Fibre additive on the physical and mechanical properties of Autoclaved aerated concrete blocks. Four sets of samples were cast and named as A, B, C and D with the fibre additive contents as 0%, 0.1%, 0.2% and 0.3% respectively (by dry weight of all the ingredients).Each sample set consisted of three specimens and the average value of the three samples were taken. For example, the average value of the three specimens- A1 , A2 , and A3 was taken as A and so on. Fibre additive influenced the aeration process of Autoclaved aerated concrete by increasing the rising/aeration time by 8%. The investigated fibre additive increases the compressive strength by 0%, 10%, 24% and 13.8% respectively to the added fibre contents of 0%, 0.1%, 0.2%, and 0.3% respectively. The optimal content of Alkali-Resistant Glass Fibre additive to be added for obtaining the highest compressive strength is 0.2%. Further investigations have shown a slight variation in density (about 0.2%) between the normal and modified Autoclaved aerated concrete blocks.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5353
Author(s):  
Khaled A. Eltawil ◽  
Mohamed G. Mahdy ◽  
Osama Youssf ◽  
Ahmed M. Tahwia

Experimental work was carried out to study new fine aggregate shielding construction materials, namely black sand (BS). The BS effect on the mechanical, durability, and shielding characteristics of heavyweight high-performance concrete (HWHPC) was evaluated. This study aimed at improving various HWHPC properties, concertedly. Fifteen mixtures of HWHPC were made, with various variables, including replacing 10% and 15% of the cement with fly ash (FA) and replacing normal sand by BS at various contents (15%, 30%, 45%, 60%, 75%, and 100%). The test specimens were subjected to various exposure conditions, including elevated temperatures, which ranged from 250 °C to 750 °C, for a duration of 3 h; magnesium sulfate (MS) exposure; and gamma-ray exposure. The effects of elevated temperature and sulfate resistance on concrete mass loss were examined. The results revealed that BS is a promising shielding construction material. The BS content is the most important factor influencing concrete compressive strength. Mixes containing 15% BS demonstrated significantly better strength compared to the control mixes. Exposure to 250 °C led to a notable increase in compressive strength. BS showed a significant effect on HWHPC fire resistance properties, especially at 750 °C and a significant linear attenuation coefficient. Using 10% FA with 15% BS was the most effective mixing proportion for improving all HWHPC properties concertedly, especially at greater ages.


This paper presents the research into the incorporation of coir fiber in concrete blocks for construction purposes. Mechanical tests were performed on concrete samples containing different percentages of chopped coir fibers (0.25, 0.50, 0.75 and 1 by weight of aggregates). Density and water absorption characteristic of the samples were also measured and evaluated in relation to the mechanical properties. It was found that the average compressive strength of the blocks is in the range of 5–6 MPa and the average flexural strength is in the range of 1.04–1.47 MPa, which are lower compared to the results of samples without coir. Nevertheless, the compressive strength range of coir- concrete blocks in this study satisfies the requirements of relevant standards (SNI, AS and ASTM), specifically for non-structural or non-load-bearing concrete blocks. Furthermore, the density of the coir-concrete blocks is between 1230–1536 kg/m3 which fit into the category of lightweight blocks. Based on the results, it can therefore be suggested that the development of coir-concrete blocks is feasible for non-structural, non-loadbearing, lightweight construction material.


2020 ◽  
Vol 15 (1) ◽  
pp. 47
Author(s):  
Nurul Nazierah Mohd Yusri ◽  
Kartini Kamaruddin ◽  
Hamidah Mohd Saman ◽  
Nuraini Tutur

Sewage sludge is a by-product generated within the wastewater treatment process. Severe concern arised as the sludge are massively been dumped to the landfill and it may affect the environment. Many studies had been conducted in reusing the sewage sludge as construction material, where it is one of the optional ways to solve the issue. In this study, dried sewage sludge was incinerated with two different temperatures in order to produce sewage sludge ash (SSA), which are 800°C and 1000°C. After few processes, this SSA then reused in mortar as cement replacement with the replacement percentage of 5%, 10%, 15% and 20% by weight. The strength performance of mortar specimens was investigated after 7, 28, 60 and 90 days of curing. From the results, it is clearly showed that the compressive strength of all mortar specimens increased when the period of curing was prolonged. Moreover, almost all compressive strength of SSA mortars was higher than the control mortar. Therefore, there is potential to reuse this waste material as part of construction materials and hence, its plays an important role for future researches in minimisation of waste. 


2020 ◽  
Vol 4 (1) ◽  
pp. 23
Author(s):  
Fadhila Firdausa ◽  
Raja Marpaung ◽  
Sri Rezki Artini ◽  
Annadiyah Farah Diba ◽  
Vicky Wisma Ria ◽  
...  

<p class="Abstract">The development of technology construction has reached a period of caring for the environment. Many things been developed to support environmentally friendly construction. Itcan be started from the use of a mixture of natural ingredients into a mixture of construction materials. Concrete is a construction material that is often used in Indonesia, given its ease, price, and durabilityAlong with the development of the concrete periods has experienced many advances, one of which is in the drafting of a combined mix of making concrete, and to supporting environmentally friendly concrete, a mixture of natural materials are used as one of the making material of concrete.South Sumatra is one of the islands in Sumatra, which has an abundant plantation of rubber. The large number of rubber plantations makes rubber waste more and more, one of which is rubber seeds. Therefore it is necessary to treat rubber seed waste in order to reduce the amount of rubber seed waste and can be used to improve the economy of the surrounding community.  The rubber itself has many advantages in the industrial field. Utilization of rubber has been widely used, but no one has used rubber seeds as an aggregate substitution material in making a concrete without other chemicals. Therefore this research will discuss the rubber seed mixture as a substitute for coarse aggregate. The material used to make concrete is portland type I cement, coarse and fine aggregate from the Tanjung Raja area, and the rubber seeds used are from the Sembawa area. Coarse aggregate substitution using a mixture of rubber seeds  5%, 10%, 15%, and 20% were tested during the age of concrete of 7 days, 14 days, and 28 days.. The compressive strength of rubber seed substitution with a percentage of 5% shows the most significant compressive strength value of 19.33 Mpa. From the test results of this study it can be concluded that the greater the use of rubber seeds, the lower the compressive strength.</p>


2021 ◽  
Vol 2 (47) ◽  
pp. 72-85
Author(s):  
O. Skrypnyk

  The main indicators of the situation of regional markets of aerated concrete are described taking into account the radius of delivery of construction material from the manufacturer. The level of supply of aerated concrete in regional markets of Ukraine is estimated territorial distribution of imports. The mutual influence of factors and indicators of conjuncture of regional markets of aerated concrete is analyzed, the key factors of formation of the retail price are defined.  Peculiarities of pricing for construction materials and products in the conditions of oligopoly are characterized. The level of demand for aerated concrete in each region of Ukraine is estimated on the basis of data on regional construction volumes, regional real estate prices and regional price of aerated concrete. The relationship between the supply of aerated concrete in the regions of Ukraine and the level of prices for it is described. Based on the comparison of relative regional levels of demand and supply, the balance of the aerated concrete market in each region of Ukraine is determined. It is proved that the aerated concrete market in Ukraine has a clear regional segmentation, and pricing in regional aerated concrete markets corresponds to the Walras model, according to which price is not a function of demand (as in Marshall's theory of market equilibrium), but its factor. Regional clusters of the aerated concrete market of Ukraine have been formed according to the indicators of the level of prices for aerated concrete. Given their quantitative and qualitative assessment. It is proved that the production capacities of domestic producers together with the capacities of importers are sufficient to meet the demand for aerated concrete in Ukraine, but in some industrialized regions there is a shortage of aerated concrete. It is proposed to carry out comprehensive regulation of pricing in regional markets of aerated concrete of Ukraine by producers through the formation of effective marketing pricing policy, as well as identified areas of regulation of pricing of aerated concrete products in accordance with regional (regional) aerated concrete markets in Ukraine, which should take into account key demand factors. and offers in the region.


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