|
|
For every architectural project, once a mix design has been developed, sample panels should be built at the job site. These mockups serve as references for color and overall surface appearance. White High-Performance Concrete (White HPC) High-performance white
concrete (such as high-strength or very low permeability concrete)
adds high-tech appeal by incorporating materials like calcined clay
(such as metakaolin), slag, or white silica fume into white cement
concrete. Applications for HPC may include high-rise buildings,
bridges, and parking structures. Supplementary cementing materials may slightly alter the color of hardened concrete. Color effects are related to the color and amount of the material used in concrete. Many supplementary cementing materials resemble the color of Portland cement and therefore have little effect on color of the hardened concrete. Some silica fumes may give concrete a slightly bluish or dark gray tint and tan fly ash may impart a tan color to concrete when used in large quantities. Ground slag and metakaolin can make concrete whiter. Ground slag can initially impart a bluish or greenish undertone.
The Romans referred to concrete as
liquid stone. It was cement that allowed the most famous monuments and
constructions of the ancient world to be completed, marking the most
significant change in building design the world has ever seen. With the
use of cement, architects were freed from the constraints of the past,
from the limitations of quarried stone and its limited strength to size,
from wood and the diminutive stature its buildings always possessed.
Cement enabled the ancient architects to design with their imaginations,
instead of their restrictions.
As anyone in the construction business surely knows, cement has not yet stopped evolving. The science of cement manufacture and production is continuing to make great strides, enabling new and imaginative processes to be invented. Decorative concrete is on the forefront of this growth. With such techniques as dry pack cast stone, homeowners and designers can create an unlimited array of outdoor and textured surfaces and flooring options. These all enable the designers to escape the one flaw seen with concrete: as a finish material, its starkness can be downright plain. For instance, the durability of concrete makes it perfect for a driveway, patio, sidewalk or floor, so a means to "dress up" or disguise concrete without sacrificing any of the versatility is the goal of many of these manufacturers. Integral color One of the first ways to transform concrete is through integral coloring. This is where pigment, usually iron oxides, is added directly to the mixer. The mix is then poured normally, producing a colored slab of concrete that will not fade because the color is literally a part of the mix. These colors can range from subtle pinks and browns to deep blues and greens. This is usually done by adding a precisely measured bag of pigment to the concrete, taking into consideration the amount of cement, total yardage of the truck and individual properties of the chosen pigment. The drawback of this dry add-mix is apparent when trying to attain the same color for different amounts of cement. Because the pigment attaches to the cement, the same pigment added to a five-sack mix will be much darker than that of an eight-sack mix. "By using four distinct liquid pigments, added together in the correct ratio (similar to a four-color printing process), a huge variety of color is available," then we measure and test the resulting pigment for accuracy. Integral color has many uses for the concrete industry. Concrete roof tiles, garden accessories and pre-fab concrete pipe are all starting to use integral coloring. Other methods of coloring concrete are more appropriate for different applications. For instance, many companies make both dry and liquid color hardeners that can be scattered or sprayed on top of newly poured concrete, and once worked into the surface, strengthen the concrete while allowing the use of any color. Acid staining One of the most popular methods for decorating concrete today is with the use of acid staining. Many residential and commercial customers are using this method for obtaining a durable, beautiful and relatively inexpensive way to decorate their floors. While this concept is not new (Frank Lloyd Wright used some acid stains), innovative ideas are expanding the range of the acid stained look. Multiple stains may be used to enhance the depth of the color, grout lines may be cut into the concrete to resemble tile, or highly detailed murals or rosettes may be stained for any surface outside or inside the home. Coupled with staining and stamping, a number of options are available for designing decorative concrete. Indeed, all of the processes described here can be mixed and experimented with, limiting designers to only what they can imagine. There are a few places for the curious designer to experiment with these options. Master Builders (www.masterbuilders.com) may be widely known for manufacturing concrete materials, but they have recently helped produce an interactive online test grounds (www.concretelifestyles.com). The site allows the user to swap patterns and colors to see different styles. The most impressive thing in outdoor and indoor concrete today may be what has yet to be constructed.
Quote request form
|
Table 1: Exposures of Architectural Precast | ||
Exposure categories | Description | Techniques |
Nonexposed | Cement paste only, as removed from the form | Form finish (as cast) Form liners |
Light | Matrix dominant, surface skin of cement and sand is removed | Acid etch Abrasive blast Cast stone |
Medium | Coarse aggregate is exposed in equal areas to the matrix, 50/50 | Surface retarder Abrasive blast Acid etch Bushhammering |
Deep | Greater coarse aggregate exposure, very little matrix is seen | Surface retarder Abrasive blast |
Home
●
Cast Stone Photo Album
Cast stone & Precast Products ●
Cast Stone Colors ●
Cast Stone Textures ●
Last modified: 02/13/23
The "Dry Cast" method is a two part process, a face material to give you the similar finish to natural stone. Mechanically compacted to the rear of this is the backing mix to give the units strength in the terms of handling ability
Dry cast units are immediately demolded after casting and are hand finished to a very high standard.
Wet Cast as the name suggests produces structural products like heads and sills but is also used for San Francisco precast slabs, beams and other similar products, that are for high exposure or structural situations where greater loads are required on the finished unit. The Wet Cast also has the added advantage of specialist finishes with the use of special sand aggregates.
Cast Stone is known by a variety of other names including art stone, reconstructed stone, reconstituted stone, artificial stone and manufactured stone. This defines cast stone as any material manufactured with aggregate and cementicious binder and intended to resemble in appearance, and be used in a similar way to, natural stone. San Francisco Cast stone is either homogenous through out or consists of a facing material and backing concrete.
Semidry mixes | |
Precast concrete or sometimes referred to as 'wet' cast. |
The majority of San Francisco cast stone manufactures use the semi-dry method of san francisco precast production. And is the more commonly widely used method of manufacture. Early consultation with us is advisable to ascertain the correct method of production for your project.
Sizes: Components produced using napa Valley precast the semidry method are limited in size with face dimensions of Ashlar units normally no greater than 1200x600mm. This is mainly because of the fact a semi dry mix is used, which require rapid and rigorous compaction with hand held pneumatic tampers. The semidry method of production is best suited to traditionally sized ashlars quoins, sills, copings, door and window surrounds, etc.
Structural requirements: Components requiring reinforcement which is more complex than a few straight bars or a layer of fabric reinforcement, must be produced using the wet cast method of production. This is because it is difficult to achieve thorough compaction of semidry mixes around congested reinforcement.
Appearance: Napa Valley Cast stone can replicate a variety of cast stone Colors and Textures . The semidry method of production is used to simulate limestones and sandstones. Where a component has a particularly intricate pattern or profile including slender projections, precast concrete may have to be used in preference to the 'semidry' method. Good color matching between components can be achieved by both methods, although fineline precast textural differences become apparent at close range.
Economics: Rapid production rates with frequent reuse of molds are possible with cast stone produced using semidry mixes. Where as with the Wet Cast process a higher number of San Francisco concrete molds is required to achieve the same casting program, but careful thought a planning stages of the contract can minimize the number of concrete molds. In Fact an additional 2-3 weeks extra lead-time for standard or semi standard products can sometimes be all that is needed to achieve the same casting program.
The production of cast stone using semidry mixes differs from that of wet method in several ways.
Semi Dry ~ De-molding takes place immediately after compaction. This allows a rapid casting cycle with e.g. up to 80 or more basic components (sills, copings, etc.) a day from a single mold.
Wet Cast ~ Where as to manufacture the equivalent in wet cast it would not only take longer but you would require 1 mold per cast per day i.e. to produce 80 units a day you would need 80 molds.
Semi Dry ~Compaction is carried out by pneumatic tampers rather than by vibration.
Wet Cast ~ Compaction is carried out by vibration.
Semi Dry ~ *Separate facing and backing mixes are often used for components like ashlars, sills, heads and jambs, where the backing mix is concealed from view. Separate facing and backing mixes are used primarily to economize on the facing mix. This requires a separate facing mix to be not less than 20 mm thick at any point, with semidry cement sand facing mixes and concrete backing mixes each mix is placed and compacted in immediate succession to ensure that they are effectively monolithic.
Wet Cast ~ Wet Cast units are manufactured from a through colored homogenous mix.
Semi Dry ~ Water repellent admixtures are invariably used in facing mixes to reduce permeability. Giving a water absorption of Grade B. All constituents are accurately weigh batched with the moisture content monitored regularly. Mix batches are necessarily small to prevent any premature drying of the mix. Thorough mixing and compaction are critical to ensure that the cast stone achieves the required density (typically between 1850-2100kg/m2), compressive strength and permeability.
Wet Cast ~ superplasticisers and accelerators are used to ensure good flow of the mix during vibration and compaction to achieve a smooth, compact and blow hole free finish (where ever possible finish smooth after dressing) also to give good early strength. Typical cube tests at 7-10 Days are that of the equivalent of that of a semi dry unit at 28 Days
Standard - Cast stone items that are manufactured in accordance with our Technical specification sheets. These items could be stock items or units, which are ready to cast at the first available production slot, with no molds to produce. Products like standard head, sills or pier caps and copings. The cost of establishing the molds is not same, thus for small production runs costs can be kept to the minimum. Also not forgetting lead times can be much shorter by not having to detail, obtain approval and then construct molds.
Semi Standard - Cast stone items Products, which are similar to details within our Technical specification sheets. But say vary in length or require slight mold adaptation or modification.
Purpose Made - Cast Stone items which are manufactured in accordance with the contract documents. These units are made from new purpose made concrete molds. These would probably be specialized units, which are not contained in our brochure. We have our own in house design department, who will assist you in the process of your design advising you in Careful thought must be given in the planning process for purpose made products. Please consider the following.
Design and detailing of in house production drawings- Some times
it is of necessity to produce working drawings of Architects details
to enable production of molds.
This process can some times take any thing from 2-10 days, dependant on how long it takes to get details approved.
| |
Approval of production drawings.
| |
Production of Patterns- Sometimes it is necessary to produce units
from urethane or silicone rubber molds.
| |
This may involve the pattern being produced and before molds are
manufactured, approval of the pattern may be necessary from the
Architect or Client.
| |
Approval of production patterns
| |
Manufacture of concrete molds
| |
Production of Units
| |
Curing of units
| |
Packaging and Transportation to Site
|
Remember adequate time must be allowed for production of concrete molds.
Natural stone colors are achieved either by reliance on the color Colors of crushed rock and sands and aggregates or by the addition of pigments. White cement gray cement and a combination are often used. The use of pigments can give the cast stone greater scope in the selection of suitably graded aggregates, which permit good compaction and achieve a strong, dense mix. Iron oxides based pigments are normally used in small quantities (e.g. 0.2%-1% yellow iron oxide by weight of cement for yellow sandstone's and up to 5% red iron oxide for red sandstone). High proportions of pigment powder (above say 6 - 8% by weight of cement) are used fineline precast sometimes to achieve unusual colors like blues and browns but generally these should be avoided.
A variety of traditional ashlar finishes can be replicated with cast stone, including plain, boasted, tooled, rockfaced, vermiculated. The other ashlar finishes are normally produced from latex:sand or concrete mold liners.
Semi Dry ~ Plain finishes normally produced using sealed plywood mold liners or, where the shape, detail or longevity for mold dictates, fiberglass is used. | |
Wet Cast ~ unlike the semidry method, the wet cast mix produces a smooth cement surface which has to be removed after demolding to reveal the color and texture of the fines layer. The cement surface is removed by either acid etching or retarding the surface within the mold prior to curing and washing off after demolding to achieve a smaller large expose of aggregate. |
Here is where specialist aggregates can be used to achieve some wonderful and varied finishes and colors.
Dependant on the situation all cast stone both Wet and Dry Cast can be used. But there are limitations in the Dry Cast process as opposed to Wet Cast: -
Semi Dry ~ Components requiring reinforcement which is more
complex than a few straight bars or a layer of fabric reinforcement
are not possible. This is because it is difficult to achieve thorough
compaction of semidry mixes using a pneumatic tamper in and around the
congested reinforcement. Therefore Wet Cast is the option. |
Wet Cast ~ unlike the semidry method, the Wet Cast mix is poured into the mold as thick liquid mix and compaction is achieved by vibration. So even the more complex arrangement of bars can be compacted sufficiently. The added advantage being the need to put any secondary support like pressed or fabricated steel lintel saving costs. Also we can manufacture structural beams for larger vehicle entranceways for example. |
Cast Stone
Precast concrete
Precast concrete is usually used in lower end track homes where budget is
a concern, cast stone is usually used in higher end homes where budget is
not a major concern. The difference between 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. Fireplace mantels
or as some call them fireplace mantles look beautiful when constructed
from cast stone. Cast stone fireplace mantels are used in any situation.
The fireplace mantels are both strong and fireproof. Fireplace mantels are
a thing of beauty when made from cast stone or precast concrete. Fireplace
mantels are also made from wood. Fireplace mantels or fireplace chimneys
are the main feature in any room and a fireplace mantel made from precast
innovations cast
stone or precast concrete is a sight to behold.
Cast stone by Regency
precast
installed in California city's such as Los Angeles, Beverly Hills, Bel
Air, Ventura or Santa Barbara has to be mechanically fastened to the wood
frame of a building usually with stainless steel or galvanized
attachments, this because of earthquake codes. There are many
historical buildings in California with cast stone as part of their
facade. Cast stone in Los Angeles, Beverly hills, Bel Air, Ventura
and Santa Barbara was at it's most popular in the 1900's. In Santa
Barbara, cast stone was used extensively in the downtown district and also
in a primitive form at the Santa Barbara mission in the form of adobe, a
mixture of mud and straw or horsehair mixed with water and hand shaped
into molds. Cast stone in the City of Ventura was used mainly on
churches in the downtown area. Cast stone in Los Angeles was used in
many important buildings including the famous Los Angeles City hall.
In Santa Barbara cast stone and Santa Barbara stone were used in
conjunction in many historical buildings. Santa Barbara stone also
called Santa Barbara sandstone,A&M Victorian Designs is found mainly in Santa Barbara county,
is removed from the ground in loose form, the Santa Barbara stone is then
cut and shaped by a stonemason into useable blocks. Commercial cast stone in Haddonstone,
California precast, Adriatic precast, APS precast,napa stone, Studio Cast,CDI,ventura
cast stone, ventura precast,ventura columns, A&M Victorian Designs ventura stone
Beverly Hills was used in the Beverly Hills City hall A&M Victorian
Designs and is now used on
many residential buildings. We also supply and install granite and
We also install the products exclusively manufactured by other company's
including, Sierra concrete design, Sierra stone and Dura art stone, Stone
legends, Moonlight molds, Fineline precast, Studio cast design,
Architectural products, Haddonstone, California precast, Adriatic precast,
APS precast, napa stone, Studio Cast precast,
These products include: cast stone columns, limestone, precast concrete, precast, cast, stone, limestone, sandstone, Beverly Hills,Beverly,Hills,Beverly Hills precast,Beverly Hills cast stone, los angeles, ventura, santa barbara, los angeles precast, los angeles columns,cast stone,precast concrete,concrete sandstone designs columns,los angeles precast,los angeles columns,santa barbara precast,santa barbara cast stone, santa barbara columns,santa barbara stone,los angeles cast stone,santa barbara columns,ventura cast stone,ventura precast,ventura columns, ventura concrete columns, los angeles cast stone, Cantera stone columns, santa barbara precast, santa barbara cast stone, santa barbara stone, santa barbara columns,Studio cast design,A&M Victorian Designs Architectural products, Haddonstone, California precast, Adriatic precast, APS precast,napa stone, Studio Cast,CDI,ventura cast stone, ventura precast,ventura columns, A&M Victorian Designs ventura stone. These products include A&M Victorian Designs : cast stone, limestone, precast concrete, Los Angeles concrete columns, precast, cast, stone, limestone, sandstone, los angeles, ventura, santa barbara, los angeles precast, los angeles columns,los angeles commercial precast columns los angeles cast stone, santa barbara precast, santa barbara cast stone, santa barbara stone, santa barbara columns, ventura cast stone, CDI ventura precast, ventura columns, ventura stone, concrete molds, Malibu precast, Malibu stone, Malibu columns. We have many limestone and sandstone designs installed in the Los Angeles area.
We have installed products made by Sierra concrete design, Sierra stone and Dura art stone, Stone legends, Cantera stone columns, precast concrete,concrete columns,los angeles precast. Moonlight molds, Fineline precast, Studio cast design,A&M Victorian Designs Architectural products, Haddonstone, California precast, Adriatic precast, APS precast, napa stone, Studio Cast, CDI, precast,
Last modified: 02/13/23
|