Advanced Mix Technologies. The future of Mix materials Mix designs Innovations and effects on Projects and Placements

Transcription

1 Advanced Mix Technologies The future of Mix materials Mix designs Innovations and effects on Projects and Placements

2 Looking Forward " I never think of the future, it comes soon enough. " -- Albert Einstein While studying the occult, a teacher asked one of the boys in her class, "Can people predict the future with cards?" His response was, "My mother can." The teacher replied, "Really?" The young boy was quick to explain, "Yes, she takes one look at my report card and tells me what will happen when my father gets home."

3 Intro Thank you for the privilege of presenting to you. Mike and I have been looking forward, in an effort to figure out what we believe are some possible future changes, adjustments, and down right out of the box theories about where the future will take us. Much of the future depends on todays decisions and the effect of Green construction and developments in the distribution of water waste and other predominantly under ground uses for precast members. Of course as in anything our imaginations seem to be the limiting factor of anything that can be done.

4 The Flint Water scandal will have an effect Nationally not just water purity. Increased cost of processing water will result in big users being charged more Government Spending on infrastructure The spending of the government diverting funds from infrastructure projects to supporting illegals and refugees.

5 Cement and SCM s

6 Portland Cement Electricity and fuels costs amount to nearly 40% of total cement manufacturing costs. (Age and type of kiln) Approximately 60% of greenhouse gas emissions associated with cement production are irreducible process emissions that result from heating raw materials to form cement clinker. For each ton of supplementary cementing materials used in place of pure Portland cement, approximately one ton of greenhouse gas emissions is avoided. This practice also has the added environmental advantages of avoiding air pollutant emissions, reducing energy consumption, making use of materials otherwise destined for landfill, and increasing production capacity without installing new kilns.

7 Reduction of CO2 Emissions with the increases use of SCM Replacing 15% of cement worldwide by SCM will reduce CO2 emissions by 227 million tons. Replacing 50% of cement worldwide by SCM will reduce CO2 emissions by 750 million tons. This is equal to removing 1/4 of all automobiles in the world.

8 Metakaolin

9 kaolinite It is formed by calcining purified kaolinite, generally between F in an externally fired rotary kiln.

10 Metakaolin Usually 8% - 20% (by weight) of Portland cement replaced by metakaolin. High performance, high strength, and lightweight concrete. Precast and poured-mold concrete. Fibercement and ferrocement products. Glass fiber reinforced concrete. Countertops, art sculptures. Mortar and stucco.

11 Metakaolin Considered to have twice the reactivity of most other pozzolans During the cement hydration process, water reacts with Portland cement to form calcium-silicate-hydrate (CSH). A by-product of this reaction is the formation of calcium hydroxide, or lime. This lime is the weak link in concrete, and it reduces the effect of the CSH. When metakaolin is present in the hydration process, it reacts with the free lime to form additional CSH material, thereby making the concrete stronger and more durable.

12 Metakaolin Mix Advantages Increased compressive and flexural strengths. Reduced permeability and chloride permeability. Reduced potential for efflorescence, which occurs when calcium is transported by water to the surface where it combines with carbon dioxide from the atmosphere to make calcium carbonate, which precipitates on the surface as a white residue. Increased resistance to chemical attack. Increased durability. Reduced effects of alkali -silica reactivity (ASR) Enhanced workability and finishing of concrete. Reduced shrinkage, due to "particle packing" making concrete denser. Improved color by lightening the color of concrete making it possible to tint lighter integral color.

13 Fly Ash F Ash C Ash

14 Fly Ash Type F&C Fly ash is a very fine-particulate material that looks and feels like talcum powder and can be a tan to gray color, depending on its source. It is classified as a pozzolan and with its high silica content is used by concrete producers in the range of 10 to 30% of the cementitious portion of concrete mixtures. Fly ash forms calcium silica hydrate in addition to that produced by hydration of portland cement. 30% Replacement of cement with Fly Ash = 20 % less Carbon Dioxide Emissions.

15 Fly Ash Type F&C Worldwide, concrete is used twice as much as all the other building products combined. Concrete is everywhere: in our bridges, roads, buildings, work places and neighborhoods. And underground, concrete foundations support our infrastructure. Here s where the importance of fly ash in concrete becomes clear: More than 75% of all concrete is made with fly ash. In some states, fly ash is specified for all concrete structures. And the concrete industry is only one of the important entities using this waste material.

16 Fly Ash Type F&C Improves workability. (with microscopic, spherical-shaped particles create a more flowable, easier-tofinish concrete)

17 Summary list of fly ash s contribution to concrete Increases ultimate concrete strength. Increases concrete durability. Is more economical than portland cement. Reduces the heat of hydration. (first used in mass concrete construction in the building of Hungry Horse Dam, Montana,1948) Mitigates the risk of ASR. Increases resistance to sulfate attack. Reduces concrete bleeding. Reduces concrete shrinkage during curing. Reduces the amount of water required in mixtures. Reduces permeability.

18 The Tennessee Valley Authority s Kingston plant in 2008 EPA s sudden change of heart is the result of a massive slurry spill at The Tennessee Valley Authority s Kingston plant in Failure of Kingston s coal ash retention basins resulted in serious local flooding and the pollution of 300 acres including the Clinch and Emory rivers. Consequently, the EPA reassessed its fly ash management position and proposed a new ruling that, for the first time, would regulate waste storage and disposal from coal-fired power generators.

19 The Tennessee Valley Authority s Kingston plant in 2008

20 Ground Granulated Blast Furnace Slag

21 Ground Granulated Blast Furnace Slag Blast-furnace slag forms when slagging agents (e.g., iron ore, coke ash, and limestone) are added to the iron ore at 2730 F to remove impurities. In the process of reducing iron ore to iron, a molten slag forms as a nonmetallic liquid (consisting primarily of silicates and aluminosilicates of calcium and other bases) that floats on top of the molten iron. The molten slag is then separated from the liquid metal and cooled.

22 Ground Granulated Blast Furnace Slag

23 Ground Granulated Blast Furnace Slag Increased sulfate resistance. Increased alkali silica reaction resistance. Decreased water demand. Decreased permeability. Increased long-term strength. Less heat generated during hydration.

24 Silica Fume High Purity Quartz This byproduct is a result of the reduction of high purity quartz. For Ferrosilicon and Silicon Metal.

25 Silica Fume Ferrosilicon Standard Grade Uses Standard grade is used largely in steelmaking and foundry, as a deoxidizing agent and also as an alloying element carrier. It can also be added to cast iron as a graphitizing agent.

26 Silica Fume High Purity Ferrosilicon Uses Used in the production of special steels, and the manufacturing of electric transformers cores.

27 Silica Fume Silicon Metal Uses Used mainly in the production of aluminum alloys for foundry, automotive and aircraft industries. In the chemical industry, silicon metal is employed for the production of silane, resins, silicones and lubricants. Silicon metal is also used in the production of super high purity silicon by metallurgical or chemical routes, destined to the manufacturing of parts for electronics, computers, space communications, defense systems, and solar panels.

28 Silica Fume Dense Packing. 50X Finer than Portland Cement. Less Porosity. Improve Durability. Consumes Lime from Cement. Improves Strength.

29 Silica Fume

30 Lime Dust Advantages Enhanced Finishability. Lower water demand. Filler for SCC. Up to 20% replacement. Disadvantages Lower Strength Compared to Fly Ash and GGBFS. More Permeable product. Does not lower Coulomb ratings.

31 Rice Husk Ash Improved Workability. Increased Strength.10% opt. Impermeability. Lower Heat of Hydration. Mostly Silica = Essential For Hydration Reaction in Cement. Each year, 18 billion pounds of rice is grown and harvested in Arkansas, California, Louisiana, Mississippi, Missouri, and Texas.

32 Natural Pozzolan Sources Current trends suggest that coal will slowly be replaced by cleaner-burning and abundant natural gas as the preferred fossil fuel in a number of US power plants. Furthermore, those power plants that continue to burn coal are under pressure to reduce emissions of mercury and sulfur dioxide, either by changing coal sources or by employing technologies that can result in harmful contamination of the fly ash, through the addition of activated carbon or sodium carbonate/sodium sulfate. With regard to slag cement, smelting of iron ore is in general decline in the US, negatively affecting supply of molten slag available for granulation.

33 Natural Pozzolan Sources There is thus some uncertainty that exists regarding the availability of the most highly sought after SCMs in the decade to come. On a positive side, work continues in developing natural pozzolan sources that might be able to fill a void created if industrial by-product SCM supplies dwindle. Acceptance of limestone cements is growing among agencies, and limestone should remain readily available in the foreseeable future. It is likely that use of ternary mixtures containing limestone combined with another SCM, or combinations of SCMs, will continue to increase because materials can be paired that compensate for each other s side effects yielding a final mixture that has reduced clinker content but performs as required.

34 Chemical Admixtures

35 Chemical Admixtures Conventional Changes coming new materials EPA forcing Chemical Manufacturing Companies to leave the USA and then import their chemicals for users like admixture companies to make products for the producers of concrete not just precast. Blended Supers SCC Accelerators / Hardeners Timed Retarders Viscosity Modifiers added to Polycarboxylate High Range Water Reducers Air entrainment Will become a process And not an admixture Spheres Fibers Will become less susceptible to changes in materials and slumps

36 Water reducers Will change as the mix designs and the uses of concrete changes Hydration Stabilizers Will become more necessity than ever thought before (green and lighter) Flowing concrete More commonplace

37 Specialty Admixtures Specialty Products Water Resistant Self-healing Bacteria Infused Self-Cleaning Titanium dioxide or magnesium absorbs CO2 Self-Curing Quick Dry but not crack Coatings Treatments for Recycled Aggregates Treatments for Recycled Water Internal Bonding agents Antimicrobial internal and external Polishing Aids

38 Fibers

39 Fibers Blends Nylon Poly Micro Macro Anti-Microbial on any fiber Cellulous Blends Will be instrumental in the design of hurricane, tornado, even tsunami construction

40 Aggregates

41 Aggregates Sand Natural Manufactured Sea / Silica Foundry Synthetic Crushed Glass Particle Distribution An obscure measurement by definition relies on other definitions.

42 Aggregates Coarse and Intermediate Gravel Limestone Granite Trapp Light Weight Synthetic Crushed Glass Recycled Crushed Concrete Preblended for Customers

43 Water

44 Water ASTM Says Potable Well City Stored Recycled Hot Water Methods Cold Water Methods

45 Effects on Mix Designs in the Future Considerations for mix designs in the future will be specification and material driven and unfortunately government intervention will play a role in the availability of materials. There may be use of 4 or 5 cementitious materials and as many as 4 or 5 aggregates admixtures will drive the mixes to preform. Water regulations may prevent using above certain w/c for your reported cement usage. Or the use of recycled aggregates and water may require an admixture to make the water neutral ph. Air entrainment will be required for Freeze thaw or just to help with paste content in a flowable mix. Bacteria storage requirement and dispensing equipment to add to the concrete to make it heal itself.

46 Possible Mix may be Cement 250 GGBFS 275 Metokalin 90 Lime Dust 175 Natural Sand 800 Recycled Glass Sand 600 Recycled Crushed 8 s 500 Lightweight 6 s 220 Crushed Gravel 57 s 900 Recycled Water Admixtures

47 Regulations will effect future. The U.S. Labor Department on Thursday , issued a new rule that greatly reduces the permissible exposure limit to silica dust and adds medical monitoring regulations for employees who are commonly exposed to silica dust for long periods of time. While various industry groups and NPCA are considering challenges to the rule, issued through OSHA, employers are required to comply with the new rule by June 23, We will continue to monitor the issue and will report on its impact in the coming months. The EPA will continue to develop more ways to keep the environment and workers safer, normally at a higher cost to the producer.

48 Future Mix designs will one day be a batch system you enter the performance parameters and the automated batch plant makes what you need dumps it in the form the production line shakes it and strikes it off and moves to the next step and a new batch is made Or Printed

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50 Considerations To summarize, as the world population increases, so too will worldwide demand for concrete. Throughout history, precast concrete products have been an effective way to speed up construction and minimize disruptions to the lives of the general public. In the future, it s obvious that precast concrete will continue to be in demand. The industry will, grow with the population and the economy. Precast concrete is an amazing and innovating industry, it has shaped the world so far and will definitely continue to do so in the future.

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