2.6.2 Hardened properties of colored concrete
A) Compression test
Valeria Corinaldesi, et al. evaluated compressive strength of concrete. The Compressive strength of concrete was determined at 3, 7 and 28 days age of curing. The addition of both red and blue pigments caused a certain strength loss never higher than 3 MPa. Moreover, the use of CaO together with shrinkage reducing admixture (SRA) allowed to fully recovering the slight strength loss due to the red pigment addition. At the dosage of 20 kg/m³ slightly reduces concrete compressive strength. The use of shrinkage reducing admixture and CaO proves to be very effective in reducing the risk of concrete cracking and it also gives positive contribution on concrete compressive strength
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studied the properties of pigment dyed concrete interlocking blocks (CIBs). The coloring agents used were synthetic iron oxide pigment and brown iron oxides there were produced from steel manufacturing. Ordinary Portland cement, sand, stone dust and pigment are used to manufacture CIBs. The used iron oxides consisted of brown iron oxide (A) and iron oxide pigment (B). Pigment A, and Pigment B had very little difference in flexural strength. When combining Pigments A and B, a maximum strength was obtained with a mixing ratio of 6 – 8% and 4%, respectively; it is suggested that for optimum performance, this mixing ratio be used in the case of the red interlocking block. The increase in strength by Day 28 was 24% on average compared with the age of 3 days. By Day 91, strength improved by 18% on average compared with day 28. In case of the colored block, the strength of the (50mm) thick base layer was remarkably higher than that of (10mm) thick colored facing layer. However, in case of whole colored block, as the colored layer with low strength is located at the bottom of block, the flexural strength was considerably declined, compared with the partially colored block. The change in strength as a result of the concentration of pigment was as follows: The brown iron oxide and iron oxide pigment showed the highest strength at a mix ratio of 6 – 8% and 4%, respectively; it is suggested that this mix ratio be used to achieve optimum performance levels …show more content…
Strong color can usually be produced with less than 10% of added pigment. Different color intensities are achieved by varying the amount of coloring material or by mixing two or more pigments. Red, dark gray and other shapes are produced very satisfactorily by using normal cement. ACPA stated that admixtures that contain calcium chloride should be avoided since it can cause discoloration [39]. Buehrer et al, stated that adding extra water to increase the slump may cause excessive bleeding and non-uniformity in color, using any admixtures that contain calcium chloride should be avoided. Calcium chloride may cause salt deposits to be formed on the concrete surface and discolor it
Introduction: Primer paint is used to improve paint adhesion. At ZMD, an aerospace company manufacturing commercial aircraft, primer paints are applied to several aircraft components. ZMD’s Aircraft_Series_900 design specifications call for a primer paint, with a minimum adhesion force of 4.0N. As a process engineer at ZMD, I am conducting this study to identify areas of opportunity for quality improvement. For this purpose, I have taken the initiative in researching the alternative brands to the primer paint currently used. To analyze these brands, I have requested sample data for three alternatives along with the one currently in use.
Since the first Africans arrived in what is now present day America in the 1500s, there has been reaffirming data supporting the importance of community to people of African descent. Despite large efforts to destroy this aspect of the African experience, many African Americans have maintained their kinships especially when the foundation is birthed from ethnic parallels. As a result of this affirmation, Dr. Mary Pattillo’s assertion on the present day black middle class and their commitment to restoring their community of North Kenwood- Oakland in her book, Black on the Block is no surprise. However, what is shocking is that the same declaration cannot be said for the African American middle class during what Dr. Pattillo deemed the ‘Black
To solve this problem, I built different sized cubes (2 x 2 x 2, 3 x 3
In this artwork the the majority of the painting is painted in middle tones, however there is also a dark contrast created by the Cypresses.Cool colors are dominant throughout the artwork except for the warm yellows of the wheat field. He uses the color scheme of green, blue with green, and yellow which is the analogous color scheme. These colors that are next to each other on the color wheel and white give the artwork a color harmony with using few colors. The mountain with the light blues that seem to be pushed back way in the distance is created due to the Arial perspective. On the lower third is where the horizon is and the elements are placed to lead the eye throughout the painting and straight to the vocal place which is the Cypress trees.The
Brayden falls in the concrete operational stage in Piaget stages of development. I placed him in the concrete operational stage based on his logical responses to questions about conservation, his manipulation of variables, and his response to hypothetical situations. When I asked Brayden to explain the saying “Don’t cry over spilt milk”, his response was, “it means cheer up.” I also asked him to explain the saying “Better to light a candle than to curse the dark.” He responded “it means to not be afraid.” Although these answers may have not been correct, he still answered them by giving his own figurative explanations. Brayden continued to use figurative language when asked more abstract hypothetical questions such as, describing a friend. He described a friend as being someone who will be there and play with you at all cost.
The speaker of Mending Wall allies himself with the insubordinate energies of spring, which yearly destroy the wall separating his property from his neighbor's: "Spring is the mischief in me," he says (CPPP 39). This alliance at first has the effect of setting the speaker against the basic conservatism of his neighbor beyond the hill, who as everybody knows never "goes behind his father's saying": "Good fences make good neighbors." But the association of the speaker with insubordinate natural forces should not be permitted to obscure an important fact, which has been often enough noticed: he, not the neighbor, initiates the yearly spring repair of the wall; moreover, it is again he, not the neighbor, who goes behind hunters who destroy the wall in other seasons and makes repairs. So if the speaker is allied with the vernal mischief of spring and its insubordinations, he is nevertheless also set against them in his efforts to make the stones of the wall balance and remain in place: "Stay where you are until our backs are turned!" he wryly says to the stones. Here, in fact, the speaker is rather like those of Frost's earlier poems "Rose Pogonias" and "October," each of whom, in imagination at least, attempts to arrest the naturally entropic and destructive forces of nature in the hope of achieving a momentary stay against confusion. In "Rose Pogonias," for example, we read:
The White apron is a powerful play about socioeconomic problems and inequality in our community. In the play we are introduce to two main characters, the madam and the house cleaner. Secondary characters include the distinguish gentleman and swimmers on the beach. The play takes place on the beach during the month of March. In the beginning of the play, the author reminds us the readers the immediate difference between the physical appearances of the two women. We are also made aware that there are not only physical differences between the two women, but also that of social status and financial stability. The madam is a woman of her thirty; she has light hair and has a somewhat attractive face. We also know that the madam has a husband and a young son. Whereas the maid is in her twenties, she has a fair complexion, black hair, placid and pleasant face. She is from a lower social class.
The framework that supports Roofs, ceilings, floors, interior trims and coverings, and exterior trim and coverings. Two types or purposes Bearing and Non load Bearing --carries the weight from above, such as ceilings floors roofs most exterior walls tend to be bearing partitions Some more than others. Eve sides carry more loads then the gable sides. Non bearing walls serve only one purpose and that is to separate Materials- 2x4, 2x6 most exterior walls are going to be framed with 2x6 material for the one purpose of more insulation.
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.
[20] BS Part 116: 1983. Testing Concrete and determination of compressive strength. British Standards Institution ;
Concrete is a composite material used widely in the construction industry. Concrete is basically a mixture of cement, water, aggregates and admixture (sometimes). Cement is a fine gray powder that consists of oxidizes calcium, silicon and aluminum. The aggregate used is normally gravel, crushed stone or sand. Admixture is a solid or liquid substance that gives a certain characteristics of the concrete. The cement reacts with water chemically and binds the aggregates together through a process called hydration during hardening or curing of concrete. It means that water helps in the hardening of the concrete while the cement bind the aggregate and also react with water to form a solid mass.
Have you ever caught yourself doing something you believed had no purpose in your life? In the poem "Mending Wall" by Robert Frost, a man is faced with the same problem. After having spent years mending a wall, he begins to question the purpose this wall might have in his society. Frost wants the readers to stop blindly following traditions and instead to look for the deeper meaning they might have. Frost demonstrates this by using irony, frequent repetitions, metaphors and dramatic shifts in the poem.
Author observed that overall performance of concrete was increased and there is huge reduction in water absorption [19]
The durability of cement paste is one of the most topical field nowadays that economic restraint and conservation will remain the rule of the day. The term "degradation" means that the cement paste fails to serve the intended purpose for the length of time expected. It should be noted that normally, cement paste often does have an essentially indefinite life span, in the absence of degradation processes [32].
studied the advantages of using a mortar-based mix design methodology for C-SCC. Many mortars and colored SCC were prepared including different pigments shape and fineness. Synthetic pigments are extensively used as color agents in cement based materials (Ordinary ‘‘grey” Portland cement (G) or white Portland cement), their requirements are included in many sources (Bower et al, 1964 and Buehrer et al, 1987) [28-29]. Three iron oxides yellow (y), red (r), black (b), carbon black (c) and two copper phthalocyanines blue (phg) and green (phg) were used. Some pigments can strongly increase air incorporation in fresh concrete, as in the case of the cupric phthalocyanines (Barragan B.E. et al, 2008) [30]. Mortar tests are also effective to detect this fact. It can be seen a significant increase in air content appears when phthalocyanine pigments were used; as a consequence notable reductions in strength must be expected