when did lightwieght aggregate concrete used firstly?
435765
the ancient romans,,,they were also the first to use  flyash as an admixture...
85887
Apparently as early as 1552 BC, according to the site below.
1072725
Concrete has limestone,calcium crystals etc,so even if you heat it at high temp or low or leach it ,transparency won't happen.\n  But, optimally cooled resin is transparent and can be used to set biological preserves , infrastructural support etc, but cant be used for large structures.The acid test lies in at which rate you cool it.
154903
typically this is determined by the company making the admixtures.  If you do not have access to high range water reducers/superplasticizers then you are not going to make it happen without segregation and a w/cm ratio that will make it useless.\n\nAlso SCC is very dependent upon the gradation of the aggregates, it has much more in the way of fine aggregates than standard concrete mixes.\n\nHere's a rough example:\n780 pounds cement\n1300 pounds sand\n500 pounds 3/8" chips\n1000 pounds 3/4" nominal diameter aggregate\n36 gallons of water\n\nThe admixture dosages are going to be different depending upon the company making the chemicals.\n\nThis is rough and would end up with an overyield.  SCC is something that to be developed you need a lot of experience or a lot of test batches.  Also go to the Precast/Prestressed concrete institute website.  A while back they had a preliminary guide regardint SCC
530477
In the 1920s, Americans used soap flakes to clean their laundry. The flakes performed poorly in hard water, leaving a ring in the washing machine, dulling colors, and turning whites gray. Procter & Gamble began an ambitious mission to change the way Americans washed their clothes. Researchers discovered two-part molecules which they called synthetic surfactants. Each part of the "miracle molecules" executed a specific function--one pulled grease and dirt from the clothes, while the other suspended dirt until it could be rinsed away. In 1933, this discovery was introduced in a detergent called "Dreft," but it could only handle lightly soiled jobs. The next goal was to create a detergent that could clean heavily soiled clothes. That detergent was Tide®. \n\nCreated in 1943, Tide detergent was the combination of synthetic surfactants and "builders." The builders helped the synthetic surfactants penetrate the clothes more deeply to attack greasy, difficult stains. Tide was introduced to test markets in October 1946 as the world’s first heavy-duty detergent. Consumer response was immediate and intense. Tide detergent outsold every other brand within weeks. It became so popular that store owners were forced to limit the quantity purchased per customer. \n\nTide detergent was improved 22 times during its first 21 years on the market, and Procter & Gable still strives for perfection. Each year, researchers duplicate the mineral content of water from all parts of the United States and wash 50,000 loads of laundry to test Tide detergent’s consistency and performance.
1016044
1960\n\nhttp://www.atmmarketplace.com/futurearticles.htm?article_id=16524&pavilion=112
813260
That depends greatly upon the mix design (what the concrete is made out of). Mix designs can put concrete anywhere from 50 lbs/CF (using very light weight rocks and other items), to over 200 lbs per CF.\n\nGenerally, most of your everyday concrete (3000 psi, Type II cement, run of the mill stuff) is about 150 lbs/CF, give or take a couple of pounds.
647683
wat yah mean by concrete by d way!?!?
296138
Each mix design for concrete will vary the weight and density of the mix. Air entrainment, water to cement ratio, coarse stone% and fine aggregate%, cement content, admixture content, fly ash substitution all contribute to the variation in weight. I do agree that 150 lbs per cubic foot is a recognized average when calculating concrete weight. since there is 27 cubic feet in a cubic yard, (150 lbs x 27 cubic feet) one cubic yard equals 4050 lbs or 2.025 english tons.
723118
YOUR DEALING WITH SALT WATER SO A DERIVITIVE WOULD BE ANTI AGRESSION TO THIS  SOME CONCRETE COMPANIES MAY HAVE THIS TRUE ANSWER\nANTI CORROSIVE PROTECTANT \nSEE IN FLORIDA WE USED A ALUMINUM BASED METAL BUT CHECK WITH THE CONCRETE MANUFACTURES IN YOUR AREA
812873
I used to tell people they needed a concrete softner to fix problems in their sidewalks. \n\nWe used to tell the new students to bring us 'left' handed wrenches.\n\nAnd George Carlin made reference to a left nostral inhaler.
645895
A monolithic concrete floor is poured completely before finished, and hardens as a single concrete structure.   The exceptions to "monolithic" would be a structure that has concrete footings upon which a wood or concrete floor is added later.  There is no "adding later" when you do a monolithic slab ... any stiffening beams or footings are ONE with the floor, and vica-versa.
1045289
the earliest online process
1094380
In 1871, Chicago suffered a devastating fire. In the years that followed, however, instead of recovering slowly, the city experienced explosive growth, and it quickly began to strain against its natural boundaries. By the 1880s, the available land for new buildings in this area could not keep up with demand; the only alternative was to build up. But in order to achieve the desired height, construction techniques had to change. A new method of building was developed that used a grid of steel beams and columns that were strong enough to support any stresses or forces a building might experience, including both the weight of the floor and the building contents, as well as the force of wind or even, in some areas, earthquakes. And with this new building method, the skyscraper was born and the race for the tallest building began.    Louis Sullivan is actually normally called the Father of the Modern Day Skyscraper, he was a mentor to Frank Lloyd Wright
495467
http://www.acstones.com/gemofmonth/2001/gemofmonth.8.01.html
582537
On 2002 , Check this link : \nhttp://www.carrefour.com.eg/aboutus.asp
870193
Several years ago. Around 2000.