This paper evaluates the effect of heat on the compressive strength of concrete by way of comparing the strength of concrete that is subjected to heat treatment with unheated one. Concrete ingredients available locally were obtained for the production of concrete cubes into a dimension of 15x15x15 cm. A total of 12 cubes were casted and then cured at room temperature (28 °C). The cubes were divided into 4 sets. Each set comprised of 3 cubes for each Water-Cement ratio. Two of these sets were cured for 14 and 28 days out of which one set each was heated at a temperature of 200oc for about 4 hours. They were then crushed subsequently to compare their strength. The results revealed that at the 14 day curing, the average compressive strength for …show more content…
Research results have been included in various design norms and guidelines. However, the research object usually has been traditional concrete with a compressive strength of between 15 and 30 MPa.
Ghani et al (2006), determined the effect of temperature on different properties of concrete using different mix ratios of 1:1:2, 1:1.5:3, and 1:2:4, and water-cement ratios of 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60, for cubes, cylinder sand beams. The concrete produce were cured in different room temperatures of 5oc, 55oc, and 28oc.Based on theirs, the following assertions were made.
“(i)The high temperature during curing causes an increase in initial compression strength of concrete that is, the initial compressive strength was lowest for 5 °C, high at room temperature while highest at 55
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2 4 6 2 4 6
Age of cube (days) 28 days 28 days 28 days 28 days 28 days 28 days
Weight of cube (g) 8100 8120 8090 7779 7818 7721
Density of cube (g/cm3) 2.40 2.41 2.40 2.30 2.32 2.25
Total compressive force (kN) 570 610 560 510 550 515
Compressive strength (kg/cm2) 25.3 27.1 24.9 22.7 24.4 22.8
Average compressive strength at 28 days for unheated cubes = 25.8N
Average compressive strength at 28 days for heated cubes = 23.3N
From the tables it can be ascertained, the fact that from practical observations, thehigher thermal treatment temperature results in alower final strength of concrete (Shehab et al, 2013).
There clear differences in the average compressive strength of heat and unheated cubes for both set crushed after 14 and 28 days as shown in the figures.
6.0 Conclusion
Based on the experimental results presented in thispaper, conclusion may be drawn from the results obtained thatthe strength of concrete decreases as it is exposed to high rise temperature, which attested to the fact that increase in temperature increases initial concrete strength while at thesame time it reduces its long term
We started by testing the time it takes for sugar cubes to dissolve in boiling water. We boiled the water to 100℃ and then dropped four sugar cubes in, each cube took exactly 1:03 to dissolve. After testing the boiling water we switched the beakers, which we kept the same size and filled it with room temperature water. We made the room temperature 22℃ and then dropped four new sugar cubes in, this time it took the cubes precisely 4:52 to dissolve, so lastly we tested cold water temperature. Again switching
Many people go through tough struggles in their lives, but no one really sees it, and most of the time no one really cares. The Rose That Grew From Concrete was written by Tupac Shakur. In this poem the author uses conflict, the characters, and mood to illustrate that just because something shouldn’t happen doesn’t mean that it won’t happen.
What are earthquakes? An earthquake is what happens when two pieces of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter, or focus.
At the atomic level, a small gap is left between slabs of concrete because on a hot day, the atoms that make up the concrete slab will get more energized due to the heat. When an atom gets energized, it starts moving faster and taking up more space. This causes the concrete slab to expand, until it closes gap. When the concrete slab starts cooling down, it will contract, leaving the gap opened once agian. If a gap was not created, during a hot day, the concrete slab will have no space for the exapnsion to happen without damage caused, and so, it will get damged and it can damage its surroundings. This process of the expanding and contracting concrete
If work-hardening is performed at elevated temps it is said to be hot-worked. In contrast cold-working is done right around room temperature. In both situations the work hardening increases the strength and hardness because of plastic deformation. This causes atoms in a crystal to become disordered, which means that the atoms have moved into a disordered structure. This then raises the strength and hardness by impairing the easy movement of dislocations. Cold working was done at first along with harness testing, once familiarized with all of this testing relationships between hardness, microstructure, and degree of work hardening of brass were
Concrete poetry presents its readers with a unique and often confounding situation. In addition to using language or parts of language in non-traditional ways, concrete poetry also uses elements that are more commonly associated with visual art. However, concrete poetry is not visual art. It is still concerned, primarily, with the use of language, generally to communicate some meaning to the reader in a way that is undeniably linguistic in nature. Concrete poetry is therefore an especially unique genre that draws upon and incorporates many different concepts from a variety of disciplines in order to fill in the gaps left when traditional grammar and syntax are eschewed.
Based on the above data and the requirements that are to be achieved for the construction of the dam are analyzed. Self compacting concrete has been used mostly in the design of major parts of the dam.For the first time China used new type of admixture known as Glenium type PCE admixture (PCE-3) for the mix used in constructing the power house.The SCC mixture contains large content of limestone powder to increase fluidity,cohesiveness and limit heat generation.These materials are less reactive and reduces the problem of fluidity loss of concrete.Three types of mixes have been used they are....
In this paper we have studied compressive strength of concrete by replacing natural aggregate with recycled aggregate by 25%, 50% and 75%.This mixture formed in the sample of cubes of dimension 150x150x150mm3.
ement occupies approximately 50% of the mixed concrete volume and is responsible for physiomechanical properties of concrete. Cement production is essential to infrastructure and building construction, creating demands in very large quantities. Energy resources invested in the production process and resulting greenhouse gas emissions have become problematic. The cement production process has become among the world’s largest anthropogenic sources of carbon dioxide emissions, contributing to approximately 5% of global anthropogenic CO2 emissions, (WBCSD, 2009). Increased pressure is being placed on the industry to reduce CO2 emissions, owning to awareness regarding sustainability....
Concrete today is considered by many modern engineers and architects as a more efficient and effective alternative to steel n regards to the creation of buildings, ranging from low-story apartments to neck-breaking skyscrapers. Through the rapid growth and development of the world's major metropolises and growing cities, concrete today has become one of the most important building materials to date. According to the World Business Counsel for Sustainable Development (WBCSD), “it has become the most consumed substance on earth, only superseded by water, with three tons for each person used annually” (World). This huge demand for concrete makes the cement industry one of the world's largest carbon dioxide producers, accounting for about five percent of all man-made pollution. “Approximately one ton of carbon dioxide is put into the atmosphere for every ton of cement used” (World). The cause for this problem is the increase of the global population and the increasing demand for land and energy. It's effect is that as the population continues to increase, it forces builders and developers to meet the quota of creating unlimited amounts of infrastructure within a limited resource-filled world. Knowing this, a proposed and widely agreed solution is to make the concrete in an environmentally-conscious way that will incorporate more demolished concrete, scrap from past projects, and other recycled aggregates.
Concrete is one of the world’s most popular construction materials. Some six billion tonnes of concrete is produced each year in the world, making it approximately one ton of concrete for every human being per year (Fardis, 2012, p.116). However, the lifecycle of concrete does not make it the most sustainable building material at the moment. Because of limited natural resources, concerns over green house gases, and landfill problems, concrete production is being cut-back, or at least cannot be increased to keep up with population increase. In this essay, I will look at what makes concrete an unsustainable material and possible solutions to make concrete a more sustainable material.
The impact of construction law on the construction professional: A personally contextualised exposition Jessica Lambert As I am a construction lawyer, I am not directly affected by construction law in my professional capacity. Rather, my clients, the construction professionals, are the ones who are directly impacted by it, be it through regulation, business ventures, or legal disputes. For this reason, this exposition will focus on an example involving the directors of a plumbing services company as the construction professionals, with a note on how the law in question has impacted the service I provide to my clients.
In this report, we will introduce and illustrate on precast concrete, pre-stressed concrete, ready-mix concrete, reinforced concrete, terrazzo and Urbanite in details.
Introduction This report concentrates on depicting the distinctive sorts of the building construction systems. Construction usually differs from manufacturing in that manufacturing commonly contains a mass number of comparable things without a designated purchaser, while construction normally takes spot around area for a known customer. Construction systems need aid those routes previously, which materials are joined together to build those components of a building. They might a chance to be ordered as stated by the impostor of the framework under heavyweight also lightweight development. The mechanized building construction system and the traditional building construction system are the two types of building construction system that this report will discuss.
Toughness is the ability of a metal to mutilate plastically and to absorb energy in the process before it breaks or fracture. Metals can be heat treated to alter the properties of strength, ductility, toughness, hardness or resistance to corrosion. This can be done by using heat treatment processes which include precipitation strengthening, quenching, annealing and tempering. Annealing and tempering are the most prominent methods for treating metals. A material may become more or less brittle, harder or softer, or stronger or weaker, depending on the treatment used.