Head Concrete
Compaction device for Concrete Brick Machine
A compaction device for a concrete brick machine, comprising a mold formed with cells opened at the top and at the bottom, and filled with a no-slump concrete mix. The mold freely rests either on a pallet or vibrating table, which acts as bottom wall for the mold. Compaction shoes, equal in number to the number of cells in the mold, are sized, configured and positioned above the mold so that they may snugly fit into the mold cells.
With the mold held stationary, the support table or pallet may thereafter be moved down away from the mold to allow the concrete blocks to be dislodged from the mold by the downward movement of the compaction shoes. Alternatively, the shoes may be held stationary, above the pallet standing underneath and the mold is moved up, leaving on the pallet a row of dislodged blocks.
Present day skilled manufacturers use a machine which, broadly speaking, has a feed zone where a hopper pours a no-slump concrete mix of any chosen water/cement ratio into a drawer which is thereafter moved laterally and over the vibrating cellsof a mold standing in an adjacent compaction zone. After the cells are filled with the mix, and initially compacted a predetermined lapse of feed time, the drawer is returned to the feed zone, being provided with suitable means to scrape off the tops ofthe cells, as it moves back to the feed zone. Final compaction, while vibration is going on, is achieved thereafter during a predetermined finishing time, by means of a plurality of fixed compaction shoes, provided at the lower ends of a like number ofsolid rod or tubing of fixed lengths, of which the upper ends are also fixedly mounted on a vertically movable head plate. For final compaction, the head plate is moved toward the mold, or vise versa, and a given pressure is then applied to the headplate, and hence, to the mix in each cell, by the fixed compaction shoes with or without vibration applied to the head plate and of course transmitted to the compaction shoes, that are solid with the head plate, as aforesaid. After a predeterminedperiod of time of vibration in this last position, finished concrete blocks, are moved out of the mold onto a steel plate or on a steel pallet.
A major difficulty with this type of equipment is that, because the compaction shoes are located at the ends of solid rods or tubings of equal length, and have their flat working surfaces constantly at the same level, that is in the samehorizontal plane, final compaction pressure is unequally applied in the various cells, even with vibration on the head. Indeed, the cells are never equally filled and compacted when the drawer backs up, even so, that the top surfaces of the mix in allthe cells are at the same level. Thereafter, when comes the final compaction with the compaction shoes, the result is that the concrete mix is fully compacted in some of the cells, and less in others during the period of final vibration and thereforethe density in the resulting blocks is not equal. It follows that, the less dense blocks do not have the expected or required physical properties capable of meeting the stiff specifications of CAN3-A231,2 or A.S.T.M.C936-82 for concrete paving stones,or other concrete blocks for which utmost density, and hence particularities of physical properties, is a most important requirement. In addition of not making full use of the cement powder, these less compacted or dense elements are prone to failprematurely, or do not have the same properties anticipated. For these reasons, the quality of the finished products is variable and some may have to be rejected. Likewise, other concrete blocks which are less compacted by present day methods, fail tomeet their anticipated physical properties and specifications.
Extensive research has demonstrated that all physical properties of a concrete block resulting from a no-slump mix, are very closely related to the density of the compacted mix and this holds true at all water/cement ratios within the no-slumprange. This includes the lowest W/C ratio where a minimum of water is necessary to complete the hydration of the cement. But, the same does not apply so significantly to a slump, or near slump, concrete mix where maximum or near maximum density is moreeasily obtained in each cell due to the hence better workability of the mix, and, where also the physical properties are more uniform but where compressive strength or any other physical properties are often inadequate for different type of concreteblocks or intended to be exposed to severe conditions. It can also be verified that a higher W/C ratio mix may give a higher compressive strength than a lower one due to its better workability and greater density, but such is not the case of itsphysical properties.
Abram’s law which states that the compressive strength of concrete is inversely proportional to the W/C ratio in the mix, applies to a no-slump concrete at any W/C ratio of the no-slump range but it is verified that the Abram’s law holds trueonly if the proper maximum density is reached for all mixes in that ratio range. The compressive strength, flexural strength, durability and permeability are therefore functions of the density at any particular W/C ratio in the no-slump range and anydrop of density from the utmost one appreciably reduces the compressive strength and other physical properties. As well, further drop in density causes the undesired water absorption capacity of the concrete to increase and may render the ensuing blocksless weather resistant. Conclusively, the compressive strength and related physical properties are directly proportional to the density at any W/C ratio.
Another interesting fact, noted with lower W/C ratio no-slump concrete, is the linear percentage of the loss of weight of the initial dry mass found between 25 and 50 cycles when the mass is subjected to freezing and thawing, durability testsconducted under CAN3-A231.2M85 specifications for paving stones of ultimate density. There again, the density of the finished concrete blocks is of prime importance and losses in weight in percent of the dry mass increase radically as densitiesdecrease. This is most important and, according to the present invention, a minimum acceptable density can be obtained or found for each mix design and W/C ratio, which will permit a loss of weight of less than 1% under the above specifications and, atthe same time, provide durability of all concrete blocks when, as aforesaid, made in accordance with the present invention.
There thus presently exists a problem of uneven properties in all concrete products when made according to the present day methods, due to the fact that these concrete products do not have the appropriate minimum acceptable density for theircorresponding W/C ratio mix as above explained, with resulting uneven lower compressive strength, permeability, flexural strength, durability and related properties at least regarding an important number of concrete blocks so made.
In attempting to alleviate the problem of getting full compaction with existing machine, the industry is trying to work at higher W/C ratio to obtain a better density and compressive strength but this is achieved only at great expense in waste ofcement and beneficial properties of lower W/C ratio mix. Thus, some devices like heated shoes have been designed. They permit the use of a higher W/C ratio mix and consequently a better workability of the mix but to prevent material from sticking tothe shoes, heat has to be used. Of course, a higher workability obtained by adding water does give a higher density but unfortunately, when considering Abram’s law, a higher W/C ratio gives lower compressive, flexural and shear strengths, higher waterabsorption, higher percentage loss of weight, in durability test due to freezing and thawing, and higher shrinkage.
Also, because the mix in some of the mold cells, in present day machines, are still not sufficiently compacted, some other devices, like vibration devices on the head and/or on the foot of the block machine, have been used in an attempt to optimize thedensity. However, the same problem of inacceptable uneven compaction of some of the elements from different cells and consequently too high a disparity in physical properties of end products persist. Some cities using much de-icing salts are nowconsidering not to use certain concrete blocks like paving stones, curbs, etc. in their streets because of their poor durability. The same problem applies to other prefabricated concrete blocks like bricks or pipes where any anticipated physicalproperty such as permeability is not attained because of the uneven density at any W/C ratio mix.
About the Author
nbnyzj.com is a professional manufacturer and exporter of all kinds of Single and Multi Spring brick machine.We are a member of Building Block Association with excellent and advanced technology.You can buy cheap concrete brick machine and block machine.
|
|
NEW LOT OF 10 CONCRETE MASONRY SCREW ANCHORS~DRY WALL BOARD~BOLTS~FASTENERS~NAIL $0.99 |
|
|
NEW LOT OF 10 CONCRETE MASONRY SCREW ANCHORS 3/16″ X 2-3/4″~BOLTS~FASTENER~NAILS $0.99 |
|
|
Lot of 6 Concrete Vibrators & Heads Various Makes Models Multiquip Wacker $0.99 |
|
|
OZTEC 1.2 OZ Portable Electric 1.25 HP Concrete Vibrator 1.5″ Max Steel Head $0.99 |
|
|
Oztec 3.2 OZ Electric 3 HP Concrete Vibrator 2-3/4″ Max Head bidadoo NR $0.99 |
|
|
RED HEAD LDT-1230 CONCRETE ANCHOR SCREW 1/2″ X 3″ $1.99 |
|
|
Solid 8 POUND blacksmith iron worker Sledge concrete hammer-Japan -head only-B $2.49 |
|
|
3/8″ Red Head Concrete Drill And Anchor Kit $3.75 |
|
|
Tap-It Concrete Anchor Shells 1/4 x 1-1/2 in. Made in USA Truss Head Nylon 100pc $3.99 |
|
|
Red Head Concrete Anchoring Epcon A7 Adhesive Kit – A7-501 Kit $4.99 |
|
|
Red Head Concrete Anchoring Epcon A7 Adhesive Kit – A7-500 Kit $4.99 |
|
|
Red Head Concrete Anchoring Epcon A7 Adhesive Kit – A7-500 Kit $4.99 |
|
|
KwikTap 1/4″ x 2-3/4″ Hex Head Concrete Screws Qty:8 / Pack $4.99 |
|
|
TEN PLUS ONE 2.25″ BY 1/2″ RED HEAD CONCRETE WEDGE ANCHORS $4.99 |
|
|
EMT COUPLING SET-SCREW 3 ” Die Cast Zinc Concrete-Tight With Combo-Head Set Scre $5.93 |
|
|
BODIES LAY BROKEN/HEAD HITS CONCRETE split 7″ OOP One Percent grind metal $5.99 |
|
|
BODIES LAY BROKEN/HEAD HITS CONCRETE split 7″ OOP early-00′s One Percent metal $5.99 |
|
|
BODIES LAY BROKEN/HEAD HITS CONCRETE split 7″ OOP One Percent green vinyl grind $5.99 |
|
|
BODIES LAY BROKEN/HEAD HITS CONCRETE split 7″ OOP One Percent green vinyl metal $5.99 |
|
|
4 Primitive Moai Heads ABS Mold Soap Orgone Orgonite Concrete Plaster Resin $6.99 |
|
|
Ramset/Red Head Condrive 1000 Tapcon Concrete Anchoring System $6.99 |
|
|
Tapcon 1/4 in. x 1-3/4 in. Blue Climaseal Hex-Head Concrete Anchors 75 Pack Blue $6.99 |
|
|
25 new expanding bolt concrete anchor 1/2 x 2.25 w/nuts fits lla red head holes $7.00 |
|
|
Tapcon 24325 1/4 in. x 2-1/4 in. Concrete Anchor Hex Washer Head 75 Pack Blue $7.99 |
|
|
Red Head Concrete Anchor # WS-5860 5/8 X 6 Box of 4 $8.00 |
|
|
5-5/8″ by 3-3/8″ Red Head Wedge Concrete Anchors WS-5833 $8.00 |
|
|
25 Pcs. Hex Head Concrete Screws 1/4 x 2-1/4″ w/bit(HHT14214B)35G $8.50 |
|
|
KwikTap 1/4″ X 1 1/4″ Flat Head 25 pk. Concrete Screws $8.56 |
|
|
60 Tapcon style Concrete screws 1/4″ X 1 1/4″ hex head FREE USA SHIPPING Waz $8.95 |
|
|
BRAND NEW 16 Tapcon style Concrete screws 1/4″ X 1 1/4″ hex head Cement screws $8.99 |
|
|
3/4″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $9.00 |
|
|
1″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $9.20 |
|
|
Tapcon 3/16″ x 1-1/4″ Blue Hex-Head Screws Concrete Anchors 205 Pack $9.23 |
|
|
Swimming Pool Spa Pond Vac Head Vacuum Vinyl Concrete $9.50 |
|
|
head hits concrete 10 track american punk 7″ ex++ $9.43 |
|
|
50 Pcs. Hex Head Concrete Screws 3/16 x 1-1/4″ w/bit(HHT316114A)37G $9.80 |
|
|
50 Pcs. 1/4 x 1-1/4″ Hex Head Concrete Screws (#HHT14114A)28G $9.95 |
|
|
Forway / Red Head 5/8 Concrete Fastener 25 Piece Lot $9.99 |
|
|
Head Hits Concrete Head Hits Concrete 7″ 45 Hhc45a 2001 $9.99 |
|
|
Concrete Blonde Heads Damage Ive Done Dj Us Cd $9.99 |
|
|
Concrete Junglest Lick Him In A Him Head LC12007 R VG++ C EX (LP-8808) $9.99 |
|
|
Red Head PS1012SP Concrete Anchoring System 100 pack $9.99 |
|
|
Red Head RM-12 1/2″ drop in concrete Masonry bolt Anchor (6) $10.00 |
|
|
1-1/4″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $10.40 |
|
|
1-1/2″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $10.55 |
|
|
1″ x 8mm Head Concrete Drive Pin (100) $10.59 |
|
|
1-1/4″ x 8mm Head Concrete Drive Pin (100) $10.65 |
|
|
3/4″ x 8mm Head Concrete Drive Pin (100) $10.80 |
|
|
25 new expanding bolt concrete anchor 5/8-3″w/nuts fits lla red head hilti holes $11.00 |
|
|
2 Pack- 100 Kwiktap Concrete Screws, 3/16″ x 1 3/4″ $11.00 |
|
|
2″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $11.30 |
|
|
RADIO HEAD, LENNY KRAVITZ, BLIND MELON, concrete blonde, ” MEXICAN SINGLE CD $11.99 |
|
|
#1 or “PUNI” EASTER ISLAND HEAD ~ RAPA NUI ~ MOAI ~ TIKI GOD CONCRETE STATUE $11.99 |
|
|
20 5/8 x 5 wedge anchor carbon steel fits red head drilled hilt concrete holes $12.00 |
|
|
2-1/2″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $12.00 |
|
|
20 5/8 x 6 wedge anchor carbon steel fits red head drilled hilt concrete holes $12.50 |
|
|
3″ .300 Head Concrete Drive Pin (100) Ramset, Hilti $12.50 |
|
|
Tapcon 3/16″ x 1-3/4″ Blue Hex-Head Screws Concrete Anchors 142 Pack $12.59 |
|
|
x20Pcs Hilti Coil 5/8″ x 3-1/2″ Red Head Concrete Expansion Anchors Redhead $12.95 |
|
|
52 Powers Zamac Nailin Mush Head Concrete Anchors1/4 x 2″ (6.5 x 50mm) $12.99 |
|
|
(250) 1.75″ concrete screws hex head 3/16 in shaft $12.99 |
|
|
100 Phillips II KwikTap Concrete Screw System 1/4″ x 1 1/4″ Phillips Hex Head $13.00 |
|
|
100 Phillips II KwikTap Concrete Screw System 3/16″ x 2 3/4″ Phillips Flat Head $13.00 |
|
|
100 Phillips II KwikTap Concrete Screw System 1/4″ x 2 3/4″ Phillips Flat Head $13.00 |
|
|
100 Phillips II KwikTap Concrete Screw System 3/16″ x 2 1/4″ Phillips Flat Head $13.00 |
|
|
100 KWIKTAP Concrete Screws Flat Head 1/4″ x 2 3/4″ $13.49 |
|
|
Buildex 1/4 in. x 3-1/4 in. 24301 Steel Hex Washer Head Concrete Anchor 48 Pack $13.99 |
|
|
3/4″ .300 Head Concrete Drive Pin with Washer (100) $14.00 |
|
|
100 Phillips II KwikTap Concrete Screw System 1/4″ x 1 3/4″ Phillips Flat Head $14.00 |
|
|
1″ .300 Head Concrete Drive Pin with Washer (100) $14.25 |
|
|
2 Pack- 100 Kwiktap Concrete Screws, 1/4″ x 1 3/4″ $14.50 |
|
|
2 Pack- 100 Kwiktap Concrete Screws, 1/4″ x 1 3/4″ $14.50 |
|
|
1-1/4″ .300 Head Concrete Drive Pin with Washer (100) $14.55 |
|
|
1-1/2″ .300 Head Concrete Drive Pin with Washer (100) $14.75 |
|
|
LOT OF (100) 1/4″ X 1-1/4″ HEX HEAD TAPCONS CONCRETE ANCHOR SCREWS FREE SHIP USA $14.88 |
|
|
Concrete Screws 1/4 x 2-1/4 Hex Washer Head 100 pcs $14.95 |
|
|
6 1/2″ Concrete Hammer Head $14.99 |
|
|
The Heads w/ Concrete Blonde RARE EDIT CD PROMO Talking $14.99 |
|
|
Ramset / Red Head WEDGE WS-1422 1/4 X 2-1/4″ Concrete Anchor Trubolt ITW  $14.99 |
|
|
New sealed Red Head 1/2″ By 3 3/4″ Concrete Wedge Anchors 25 $14.99 |
|
|
Concrete Anchor Flat Head Split Bolts 1/4 x 2 1/2″ $15.00 |
|
|
Concrete Screw Hex Head 1/4 x 1-1/4 100/ct (Tapcons) $15.00 |
|
|
Red Head Concrete Epoxy Adhesive Anchoring Kit $15.00 |
|
|
Concrete Anchor Round Head Split Bolts 1/4 x 2 1/2″ $15.00 |
|
|
Ram Set Red Head 1/4″ Concrete Drop In Anchors- 52 pcs $15.00 |
|
|
2″ .300 Head Concrete Drive Pin with Washer (100) $15.25 |
|
|
Red Head 11271 1/2″ By 3 3/4″ Concrete Wedge Anchors 25 $15.29 |
|
|
NEW RUBBER CONCRETE LATEX MOULD MOLD TO MAKE BUDDHA HEAD WALL PLAQUE 2 $15.70 |
|
|
1/4″ x 2-1/4″ Phillips Flat Head Concrete Anchors Tapcon # 24380 Pack of 75 $15.99 |
|
|
(50) Concrete Sleeve Anchors 3/8 x 1-7/8″ Hex Head Nut & Washer $15.99 |
|
|
Red Head Concrete Wedge Anchors 1/2″ x 5-1/2″ Hot-Dipped Galvanized QTY. 10 Pack $15.99 |
|
|
2-1/2″ .300 Head Concrete Drive Pin with Washer (100) $16.00 |
|
|
3″ .300 Head Concrete Drive Pin with Washer (100) $16.20 |
|
|
Ramset/Red Head S-38 Self Drill 3/8″ Concrete Anchor (50 Per Box) New-Old-Stock $16.50 |
|
|
LION HEAD FACE PLAQUE CONCRETE CEMENT PLASTER GARDEN MOLD 7214 $16.95 |
|
|
Screw Drywall Anchor Power WALLDOG PAN HEAD PHILLIPS Stainless Steel Concrete $16.95 |
|
|
Red Head RL-38 Concrete Drop-in Anchors 3/8″-16 (50) $16.99 |
|
|
72 Tapcon 1/4 in. x 1-3/4 in. Blue Climaseal Hex-Head Concrete Anchors Screws $16.99 |
|
|
Aqua EZ Concrete Vacuum Head Item #: 191605 $17.00 |
|
|
THE HEADS damage i’ve done MOBY 4 TRK CONCRETE BLONDE Johnette Napolitano $17.00 |
|
|
Red Head SRM-14 1/4-Inch Multi-Set 303 Stainless Steel Anchor (100 per Box) … |
|
|
Don’t listen to the voices in your head Listen to your Concrete Contractor Coffee Mug in Metallic Colors T-ShirtFrenzy offers over 30,000 designs on tons of products to offer millions of variations. You can search our store for something for everyone on your gift list or shop for yourself (our personal favorite). Please contact us with questions…. |
|
|
Don’t listen to the voices in your head Listen to your Concrete Contractor Mug for Coffee / Hot Beverage (choice of sizes and colors) T-ShirtFrenzy offers over 30,000 designs on tons of products to offer millions of variations. You can search our store for something for everyone on your gift list or shop for yourself (our personal favorite). Please contact us with questions…. |
|
|
The Man From U.N.C.L.E., Vol. 2 [Original Television Soundtrack] $24.98 … |
|
|
Thy Kingdom Come Undone $8.99 57 tracks. Contains: Beacon to the World, The Anal Cavity Is Coming Up Roses, Disgrace Land, The Pastor’s Cock Is In My Mouth (Hooray!), Penal Abortion, I Shit God, and many more! Rising from the literal and aesthetic ashes of SWALLOWING SHIT, Winnipeg’s HEAD HITS CONCRETE pummeled and bashed and weirded and jarred their way through 5 years of existence before choking on their own vomit in 2004… |
|
|
Metal Millenium / Countdown to Armageddon [31 Crushing Songs on 2 CD's] …. |
|
|
Karcher 2.641-005.0 Pressure Washer T-Racer Wide Area Surface Cleaner T350 $69.99 Includes T-Racer Wide Area Surface Cleaner (T350) – 2.641-005.0, (2) Nozzles… |
|
|
Bostitch N66C-1 1-1/4-inch to 2-1/2-inch Coil Siding Nailer with Aluminum Housing $239.00 Nail down siding in no time with the powerful, precise Bostitch N66C-1 Coil Siding Nailer. This lightweight tool features a aluminum housing that makes it durable enough to repeatedly withstand the rigors of all-day use. And with adjustable nail depth and a soft rubber foot, you can work with a range of siding materials, including soft woods. The N66C-1 Siding Nailer works with any air compressor … |
|
|
Bosch 11224VSR 7/8-Inch SDS-Plus Bulldog Rotary Hammer $129.94 Bosch’s 11224VSR 7/8-inch SDS-plus bulldog rotary hammer offers the utmost in versatility and functionality thanks to its compact size and powerful motor. Ideal for use during overhead and down-drilling operations, the 11224VSR features an ergonomic design with a D-handle to increase control yet reduce user fatigue. Multiple working angles and operational modes make this rotary hammer a must… |
|
|
Sheep Castrator $1.99 … |
