The oldest version is referred to as Wet Casting. Gravel boards. Both are generally composed of aggregate, Portland cement, and water. The carbon uptake rate of dry-cast concrete masonry units is higher than wet-cast for the same reason. An Introduction to Dry-cast Concrete This new concrete variant calls for water to be added after other ingredients are in the mold, compacted and finished. French et al. In jointed systems, the precast structural components are separated and are connected using joint detailing like bolts and welds. Used to set mailbox posts, fence posts and lamp posts without mixing; Pour dry mix into hole and soak with water . A single bag of Sika foam costs about $16, at one bag per post hole. When done right both methods should actually. Cast Stone, on the other hand, solves both of these problems. Wet-cast paver mix contains more water than dry-cast pavers, rendering the mix a similar consistency to concrete. 3 x sharp sand, 2 x 10mm pebble or chippings and 1 x cement. Most people are familiar with the two most common types of concrete: wet cast and semi-dry cast. 1993; Park 2003; Bull and Park 1986). The wet cast manufacturing method is similar to casting in plaster and provides a close-grained dense surface. The wood column is attached to a U-shaped steel bracket made of ¼-inch steel with ½-inch thru-bolts and ¼-inch lag bolts. The system with wet connections uses cast-in-place concrete, having to follow the requirements of a monolithic RC construction [10] . has resulted in. (347. This method is typically used for the production of large diameter pipes and more complex fittings that. Precast Light Concrete. com Dry cast posts are manufactured using a semi-dry concrete mix which is compacted to give it strength. Quickrete concrete has limited workability; just tossing a mixture in a hole for a post is fine. /cu. Pure dry cast method used to join the beam column connection under pre-tension bolts. In this system, the vertical load resistant system is divided into two parts, and those. Pipe – handle in 10 to 12 hours. EZ-Tube: $187 / footing; 4 EZ-Footing sections, 1 base and galvanized rod = $157; Labor: 30 minutes (move and place the sections). A calculation method for the shear strength of concrete dry joints based on Mohr’s circle was established, and a simplified formula for calculating the shear strength of UHPC dry joints with different compressive strengths was developed. Try to get 6-8 inch of concrete all round the posts. The. Posted February 13, 2019. e. In essence Cast Stone is a highly refined architectural precast (concrete) product manufactured to simulate natural cut stone. ERNEST WILLIS* *Mr. The most common finish for a dry tamp cast stone is limestone or sandstone while the wet cast method is capable of providing a wider. Each example produces 1 cubic yard of concrete. In precast concrete con-struction, all the components of structures are produced in controlled environment and they are being transported to. Do this by nailing the sides of the tube to the center of a tic-tac-toe grid of 2x4s at the top of the hole. Dry cast posts are manufactured using a semi-dry concrete mix which is compacted to give it strength. Any good concrete company will agree that using precast concrete is also a great way to speed up the building process. 6) certain lines of natural stones products. Fun and Informative Concrete Technology Videos for Dry Cast Concrete Producers. Those pieces of equipment include:. 6) through No. Like the article. On the other hand, the spun-cast technique of manufacturing precast concrete pipes involves concrete with a w/cm ratio. Top Tread: “No. It offers the advantages of a high level of. T-FIXX ®, bolt or bar anchors transfer the tension and shear force into the precast element. Wet cast pavers also tend to be more expensive than dry cast pavers. Wet-Cast. Click on the links below to find out more about how our product compares to other materials. 0% weight loss when subjected to 300 rapid freeze-thaw cycles, as per ASTM C666. The advice of EN1991-1-1 is that the density difference between unhardened (meaning ‘wet’) concrete and the ‘dry’ density of the same concrete months later should be taken as 1 kN/m³. The concrete mix for vibrant dry tamp cast stone has zero slump while the wet cast mix includes a higher water content and has 3” to 4” of slump. For this method, we use 6×6 posts rather than 4×4 posts and use 12” concrete forms instead of 10″ ones like before. Most of the bright coloured pavers (Red, yellow and Jet black) you see would be made using wet casting process. On the contrary, with dry set concrete, you can place the post in the hole first and then pour the concrete around it. An Introduction to Dry Cast Concrete. Wet Cast Concrete Products: Manufactured from measurable slump concrete. The post-cracking behavior of fiber-reinforced concrete depends on. THE DRY CAST PROCESS. The benefit of using Sika's Watertight Concrete System is the added value and support alongside our pioneering product offering. 1 This specification covers the production of dry cast concrete as defined in 3. Precast and Prestressed Concrete Piles. PAGE 4 > Guide to Concrete Construction — Part VI-Section 20 – Precast Concrete Version 1. Design Fill – The design earth cover is reported on the plans as the elevation difference between the point of maximum fill and the bottom of the top slab. The dry cast uses very little water in the concrete mix. Both wet cast and dry cast pavers are suitable for residential projects (i. Architectural Precast Concrete vs. The next step is easier than it looks: Calculate the unit weight of the sample. It must meet the requirements of BS1217: 2008 or, better still, the more stringent requirements of the UKCSA Standard. 03. The efficiency of the dry cast process makes it possible to produce up to 8 precast sections per day. Here is an example of a mix design for different types of precast concrete. 2. Unsure of the difference between Dry Cast and Wet Cast pavers? Jason Stafford, Territory Manager, explains the difference in this 13 minute presentation. The dry-cast concrete has also been used for its advantages particularly in precast concrete industries, e. What is the difference between dry and wet cast concrete? Wet cast concrete is the liquid form of concrete we see pouring from a cement mixer, hopper, or truck. The people at Steps Plus have been producing precast steps in Syracuse since 1967. Sure this method works fine, but the contractor's method takes nearly all the hard work out of the mixing part. Wahoo Concrete - Dry Cast vs. Cast in place wall system is a wall system that is naturally a building structure system, consist of vertical load resisting the power and lateral (seismic and wind) load resistant system. Nelson Precast 1501 W Patapsco Ave, Baltimore, MD 21230 (410) 522-7190 (410) 732-3408 info@nelsonprecast. All products available ex works. The connection in Fig. 5; therefore, wet cement can produce alkaline (caustic) skin burns which progress and get worse without more exposure. This may make it appear that dry cast is stronger than wet cast; however, the tests are not controlled. In order to make dry cast stone, a concrete mixture is compacted into a mold; then immediately taken out of the mold to be put into a curing room with humidity levels of 95% for 24 hours or more. The material has a density of around. Precast versus vibrant dry tamped (VDT) cast stone. About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright. Consider these statistics from the Concrete Producer, a trade magazine focused on the concrete industry. Both wet cast PMBWs and dry cast MBWs resist horizontal earth pressure by acting as gravity retaining walls. Wet Cast Concrete Design •A significant amount of Box Culverts and precast concrete products are produced using wet cast processes, including some Reinforced Concrete Pipe (RCP). Measuring in at 9ft, it is a great choice for those looking to. To complete fences, gravel boards are also available, these are 1825mm x 300mm x 50mm size manufactured in both smooth and rockface finishes, and 1825mm x 150mm x 50mm size in smooth finish only. Dry cast uses an expensive machine, but the machine can be used for multiple slabs. The next piece is the uplift anchors that are bolted to the pre-cast post at the base of the. However, conventional dry-connections-like sleeve grouting joints in precast concrete structures lagged at a low construction and management efficiency with poor quality control. Both methods manufactured a simulated natural cut stone look. 1. 5" and are manufactured with four steel rods for reinforcement. 5) Landscaping circles. Made from wet cast concrete and reinforced with steel, this post is designed to withstand the elements and provide a secure foundation for your fence. Increased production. Given the importance of fire safety in the design of a structure, it is critical to understand the damage that may occur in the event of a fire to be able to prevent the building from collapsing. That won’t happen with foam because it isn’t water-soluble. What is wet cast concrete? Wet cast concrete is a flow-able form of concrete which may be poured from a mixer, hopper or truck. BY W. A dry-cast mixture has just enough water to initiate cement hydration within the range of 0. [1,2] TAHER [3] Classified the connections in precast concrete as dry and wet. 9. These methods can be subdivided into three basic groups according to CSI Specification 04 7200: “Vibrant dry tamp (dry cast) products, n—Cast Stone manufactured from earth moist, zero slump. Modern dry cast pavers can have surface textures that mimic natural stone and 3- and 4-color blends have become quite common. 1. This lateral system includes a shear wall, moment-resisting frame, braced frame, etc. A cast-in-place or precast wall complying with the requirements of 18. An increase in curing time means wet-cast pavers are more labor intensive to produce, resulting in a higher price point. Cast Stone Masonry Products. Intermediates & Ends = 100mm x 85mm. Increased production One benefit of using dry cast is it can be consolidated within a form. In general, casts are meant to stay dry. Wet Casting is a labour intensive process which is reflected in the lead times for our bespoke products . 6 Dry Cast – In this Standard it shall be defined as very low or zero slump concrete . 6) certain lines of natural stones products. BRICK PAVER VS CONCRETE PAVER (1) BUILDING A PATIO (1). 92 kB) Impressive and unique properties and advantages have been obtained from a new concrete variant called dry-cast concrete, which has been developed by Gabriel-Wills Associates after 4 years of intensive research and testing, it differs. Less trips to the truck plus clear time savings equals a more-efficient jobsite. 19 (No. Fire exposure can have a significant impact on the structural integrity and robustness of precast concrete beam-to-column connections. 2mm. Perma-column . Friday, January 20, 2017 If you’re not well into the concrete industry, the differences in product creation and the reason for those differences can be hard to grasp. The cast-in-place method is more common than shotcrete, but it takes more time to complete a project because of the lower compressive. Cost-effective: Due to its. Contrasting that with our semi dry stone process and you can see why Serene Stone semi dry is. However, the resultant pavers will have lesser strength. A wet cast can lead to skin irritation or infection. In this blog, we will explore the advantages of using wet cast paving over dry cast paving, highlighting its potential to transform your outdoor areas into stunning havens. An important coating characteristic that needs to be recognized when selecting coatings is the permeance of the system. In many applications, handling capacity, cost and time along with the availability of experienced personal may be the decisive factors to use either dry or wet techniques in erection process. The mixing is important to get the cementitious materials and water in contact so that a chemical reaction called cement hydration can occur. Acid Etching – Process of applying a solution of hydrochloric or muriatic acid and water to the exposed surface of Cast Stone in order to remove the cement film from the aggregates, achieving a fine-grained finish which simulates natural cut stone. The biggest difference between the two is the manufacturing process through which they are created. used w/cm ratios of 0. In recent decades, precast concrete buildings have undergone significant development, attracting considerable academic attention to their mechanical performances. These two materials also provide benefits over the other, but. in dry cast concrete products were found to increase the compatibility of mixture ingredients instead of developing a uniformly distributed, spherical air void system as found in "wet cast" concretes. For conventional concrete the fineness modulus of the fine aggregate should range from 2. 34 2 Ductile Precast Concrete Frame with Dry-Connections. Furthermore, concrete jacking pipes should be wet cast vs. Introducing our 6FT Concrete Intermediate Fence Post (1. It is usually poured at temperatures above 100 degrees Fahrenheit. Bedding material shall consist of crushed stone, cinders, slag, sand, or other approved porous material having a maximum particle size of 13. Unsure of the difference between Dry Cast and Wet Cast pavers? Jason Stafford, Territory Manager, explains the difference in this 13 minute presentation. It's even more difficult to. Now I've put concrete posts up myself in the past using the the sort of mix you mix with water. 30 lb/ft 3 (21 kg/m 3), a quantity significantly higher than would have been predicted using wet-cast concrete. One benefit of using dry cast is it can be consolidated within a form. placement”, but calls for continuous inspection for “bolts to be installed in concrete. μ = static (μ s) or kinetic (μ k) frictional coefficient. Precast concrete is cheaper for large scale constructions whereas site cast is cheaper for small scale construction. Keep your child’s cast dry during baths or showers by covering it with two layers of plastic, sealed with a rubber band or duct tape. Dry bond is used in which FRP is pre-bonded with a layer of aggregate and the fresh concrete is cast against the bonded aggregate [6]. org/education •Strength (compressive, flexural, tensile, bond) •Modulus of elasticity •Coefficient of thermal expansionPrecast concrete has significant edge in terms of strength. With their Headquarters based near Geneva, Quadra. 2) Cobble stones. Cast-in-place also has a high compressive strength of 4000 psi to 5000 psi. , Inc. [6] the degree of automation is more advanced in the precast concrete component production than any other part of the industry. The failure was developed at the interface between the region filled with cast-in-situ micro concrete and the normal concrete. Higher for SCC and Dry Cast Volume of Sand Volume of Total Aggregate 13 14. N. It isThe integrity of precast concrete skeletons depends merely on the moment transfer of the beam - column connection. 5. Fast-Setting Concrete. Landscape Planning & Process. Keep your child's cast dry during baths or showers by covering it with two layers of plastic, sealed with a rubber band or duct tape. concrete units, interlocking soil-filled reinforced concrete modules or bins or rock filled gabion baskets. In these examples, steel ranges from 43% to 53% of the total cost of components. Farm structures - Ch3 Building materials. Wet cast concrete easily fits the shape of any mold (including any stamps or imprints), allowing for ease in creating different paver shapes, sizes, and textures. A vision of over a centimetre depth of captured and condensed water is one to contemplate if pressured to lay an impermeable finish on a newly cast. Ever wonder how a dry cast concrete pipe is manufactured? In just under a minute we take you on a behind the scenes look of what goes into the manufacturing. 2 billion in. Whereas a cast stone planter uses just enough water to hold the material together, the wet process of concrete actually uses enough. Air-Dry Saturated Surface Dry (SSD) Oven-Dry Wet Aggregate Properties Bulk Density. 38 without the use of admixtures. This post is constructed using wet cast concrete, which results in a consistently smooth and durable finish. which has contributed to the rising popularity of concrete fence posts. An experimental work was carried out to examine the properties of dry-cast concrete using both types of cements (PPC and OPC). Wet Cast Paver – Techo Bloc Aberdeen. In some cases, dry-cast products can comply with specified material strength requirements in 24 hours. C1776 Specification for Wet-Cast Precast Modular Retaining Wall Units . [6] and Nimse et al. Admixtures –. 3. The observation of crack and failure behaviour of all concrete specimens were also carried out. But to produce durable cast stone, it is important to understand the mechanisms that cause concrete toIn this study, ultrahigh-performance concrete (UHPC) was utilized in precast segmental beams to reduce the self-weight, shorten the construction time, and improve the performance and durability of. As required, AAS can customize finishes for architectural precast. Color & Finish: Wet cast pavers often feature more bold color tones, smoother and more intricate surfaces, and can better imitate natural stone. Dry cast concrete has the right amount of water to hydrate the cement. Introduction Indonesia is one of the fast developing countries in the world. Romtec Utilities primarily uses two materials for constructing wet wells and sumps: precast concrete and fiberglass. Plaster casts and fiberglass casts with conventional padding aren’t waterproof. Our advanced methods consistently produce a high quality precast. Jorge explains the difference between the dry cast system and the wet cast system. With cast-in anchors you can generally get them deeper, with more reliable QA, and a more readily verifiable load path to confirm that you have developed steel within the pullout cone. Wet Cast Mixer Del Zotto offers a system that is fast, efficient and simple. The emulative cast-in-situ method and dry connection method are compared. up from the bottom of the footing. Vibrant Dry Tamp (VDT) casting method: Vibratory ramming of earth moist, zero-slump concrete against a rigid mold until it is densely compacted. Types of connectionsWe have all seen the day-old trick of dry pouring concrete in a hole method for ease of mixing, where you dig your post hole, filled it with dry bags of concrete, pour water in the hole, and mix it right there in place. Use a hairdryer on the low or cool setting. [4, 5] Wet connections rely on the splicing. May 2017. It uses complex machinery, and produces products. A dry-cast. 1, 7, 14, 28, and 56 days for those uses PPC (Figures 6 to 8), the new curves correlated between w/c ratio and compressive strength of. 3. 1 a,b shows the cleat angle with dowel bar connection and cleat angle connection, while Fig. Modular block walls (MBWs) are systems which contain dry cast precast concrete units. AAS CNC technology and experience allows for an extremely high precision mold making process that produces high-quality. Although dry cast pipes, typically used for open cut projects, have the same ultimate strength as wet cast, wet cast pipes have a higher resistance to strain and can carry an axial load of approximately 2,000 tons on an 84-in. Usually contains a slump less than 4 inches and used for production of large diameter pipe. Contrasting that with our semi dry stone process and you can see why Serene Stone semi dry is. Give us a call at 717-267-4505 for information on more quality precast, prestressed products to meet your design and construction needs. The Architectural Precast Concrete and Cast Stone products by Steps Plus have numerous advantages over other materials that are sometimes specified for use as building trim. 2. Some of the earliest concrete structures were built by trade. Repairs of Surface Defects in Cured Products:As consumers and builders recognize the shortcomings of wood in the ground, precast concrete columns have become the permanent foundation solution of choice. Precast concrete renders come in two main types – wet cast and dry cast. Reinforcing: Fibermesh and/or steel reinforcing. Wet Cast - Jorge. Dry posts are approximately 15-20% stronger and less brittle than wet cast posts. Trusted & TestedNormal human skin has a pH of 5. Five. Few terms are as self-descriptive as the one given to the Cast-In-Drilled-Hole (CIDH) pile. Wet cast vs. Determine where you want to position the post and dig the hole using a shovel or post hole digger. The most common finish for a dry tamp cast stone is limestone or sandstone while the wet cast method is capable of providing a wider array of possible finishes. Dry cast concrete fence posts, on the other hand, involve a concrete mix with a lower water content. The difference between high end cast stone and precast concrete is easily seen, and even the novice can appreciate the high quality limestone like finish on a cast stone product. Also, dry cast can only achieve limestone or sandstone texture and cannot create a smooth finish. 3. These wall panels can be used as attractive dumpster enclosures. Wet Casting vs. 2. Step 1: Digging Holes. 13 13:01 Seite 190. Both wet cast PMBWs and dry cast MBWs resist horizontal earth pressure by acting as gravity retaining walls. 6 precast modular retaining wall unit, wet-cast, n—a precast modular retaining wall unit, manufactured from con-crete using a wet-cast process. Sealers will protect concrete from both chemical and physical damage and are very inexpensive. 1 GENERAL Precast concrete elements are, effectively and by definition, elements that are manufacturedThe first precast concrete render was developed in France during the early 1960s, to reduce labour intensity and improve quality by creating a product that could be applied more easily without compromising on performance. The construction and mechanical principle of the replaceable energy dissipation connectors are introduced. Wet Cast Production Forms remain in place until sufficient strength achieved. On the other hand, dry or vibrant cast. Westbrook Concrete Block Co. Needs skilled labor: High-strength concrete requires skilled technicians to apply it properly because it is generally used in areas of high pressure and commercial settings. Engineered form panels are a popular option among precast concrete manufacturers that produce a variety of different-sized or custom products such as wing walls, special drainage inlets or “one-off” vault structures. It’s zero slump and perfect for pipes, manholes and other various products. Architectural Precast is a concrete specified material and Cast Stone is traditionally a masonry material. Below, several important facts. Customers often ask the difference between dry or vibrant tamped cast stone and wet cast stone. DIY. Concrete takes different amounts of time to solidify to a strong, rocky consistency. This method calls for the construction of a reverse mold of the required unit. It is important to keep your cast dry. The main difference between the two processes is the point at which the water is added. Precast prestressed concrete method; In the precast prestressed concrete method, high-strength steel cables, known as tendons, are placed inside the mould before the concrete is poured. This initial evaporation keeps the cast cooler than the air. 8, 18. The post must be held in place until the concrete begins to set. Therefore, concrete masonry units (CMU), steel frame, concrete or metal studs are typically built out from a backup wall with a 1” to 4” air space, which may include insulation. If the size of the opening exceeds the safe limitations of cast in the use of a structural header is used to create the required opening. Concrete is a very basic building material that adequately serves a multitude of construction applications. 8M) - a sturdy and reliable option for your fencing needs. Cast stone is a type of precast concrete designed to replicate the appearance and texture of natural stone. For best results see a professional on concrete sealing and wait at least 28 days after concrete is poured to seal it. Concrete is a hard construction material: a mixture of cement, sand, aggregate, and water in specific proportions that hardens to a strong stony consistency over varying lengths of time. Wet Cast- Uses a concrete mix that is wet relative to the mixes used in other processes. Dry Cast vs. Cost. We also do a range of styles to match the rest of your fencing. Precast Concrete vs. Wet cast product is better when a structural product is needed and where much bigger pieces need to span large openings. Cost-Effective: Due to its efficiency and time-saving qualities, dry pour concrete is cost-effective in the long run. Both wet cast PMBWs and dry cast MBWs resist horizontal earth pressure by acting as gravity retaining walls. Dry cast is tested by breaking cubes whereas wet cast is tested by breaking. 2) Cobble stones. e. It's also more weather resistant than natural stone, and can be cast in numerous colors. The sharp-ness of line of the assembled con-struction depends mainly on the ac-curacy of the manufacture of the segments. What is the difference between dry and wet cast concrete? Wet cast concrete is the liquid form of concrete we see pouring from a cement mixer, hopper, or truck. Quick Deliveries 5 Year Warranty . Typically requires less intense formwork. its rapid hardening time for fast mold removal (it significantly increases the plant. Wet-cast paver mix contains more water than dry-cast pavers, rendering the mix a similar consistency to concrete. If next to a driveway, Steps Plus can make a ornamental iron gate that attaches to the columns to span the driveway. In Videos. Mix ratio’s needed for garden ornament moulds are also a 3-2-1 mix, but the sand content is higher i. SG sample = W 1 ÷ [ W 2 – W 3 – (W 2 – W 1 ÷SG wax) ] and assume the specific gravity of wax = 0. Concrete Gravel Boards. The two longer length boards are only. Reduced Labor: The process requires less manual labor compared to traditional wet mix methods. If a railing or fence post is placed on the top of the blocks, the. Dependant on the situation all cast stone both Wet and Dry Cast can be used. Caution. Description WET CAST This product has a smooth finished appearance and has a higher water content that dry cast products. In another relevant study, a new automated detection method was suggested by Chen et al. Precast concrete kerbs shall be laid and bedded on a 50mm thick layer of bedding material, placed on the compacted subbase or other formation layer to suit the designated levels of the finished road. A wet cast can also cause irritation or sores on your skin. ASTM C1364 requires that both “wet cast” and “dry cast” produced cast stone have a maximum 5. Slump is the consistency of concrete before it. Acceptance Specifications and Precast Concrete Box Sections. It usually requires ready-mix concrete, and it is commonly used for a varied array of structural elements. The wet cast process, on the other hand, uses a much more plastic concrete mix that can be poured and vibrated into the molds. Dry Cast Concrete. From there they are put into a kiln to cure, stacked on a pallet, and sent off to distributors to be sold. 75 hours for precast vs. Wet-cast pavers also have the ability to impersonate a variety of finishes such as wood, water and natural stone. 25. genr8admin. Precast beam is casted with normal cast in place concrete for only 90 mm portion from bottom face for precast wet connection-2 (PC-CRS). ”. The ingredients are readily available and the skills required to make concrete are relatively simple. Most decorative precasters use a wet-casting method, as opposed to dry-cast. Concrete also sets in wet weather, but rainwater in the mixture can weaken it. Labor Costs Reduced by 25. The biggest difference between the two is the manufacturing process through which they are. The frictional force can be expressed as. Top 10 Facts about Dry-Cast Concrete. Pavers manufactured for Michigan. The study focused on the behavior of different beam span lengths under different column loss scenarios. Specifications; Length: 2400mm / 8ft. Vibratory compaction by hand tamp of earth-moist, zero-slump concrete against rigid mold until it is densely compacted. ” Engineered Form Panels. Cast Stone - a refined architectural concrete building unit manufactured to simulate natural cut stone, used in Division 4 masonry applications. Cast Stone can be stronger than precast concrete, and is easily cast to produce identical pieces. Ever wonder how a dry cast concrete pipe is manufactured? In just under a minute we take you on a behind the scenes look of what goes into the manufacturing. pipe on a radius of 1,500 ft. 7%) compared with three-keyed joints. 3) Bullnose stones or Coping Stones. Wet cast concrete, as its name suggests, has a wetter, more liquid consistency, or what is referred to as ‘slump’ – the state of concrete before it is cured. 2 Awesome Raw Material Alternatives If you’re not well into the concrete industry, the differences in product creation and the reason for those differences can be. So, what doesEven more clear is the definition of “Cast-in Anchor” in the same section, where it states “installed before placing concrete” (italics added). These smooth textures and bold colours due come at a cost of durability and wear resistance due to the manufacturing process. Spalling of top concrete slab at bridge joint was also reported. 38, respectively. As with wet-cast mixes, adequate curing of dry-cast concrete greatly enhances strength, impermeability, surface hardness and crack resistance. used w/cm ratios of 0.