Foamed Concrete and Lightweight Concrete

GENERAL DESCRIPTION

Foamed concrete or lightweight concrete derived from Allied's aqueous foams are suitable for both precast and cast-in-place applications. Some of the highly insulative cementitious foams at densities 48 kg/m³(3 pcf) to 645 kg/m³(40 pcf) or higher can be used as block fills, lightweight roof deck and void-fill materials. Good strength characteristics with reduced weight make lightweight concrete based on Allied's aqueous foams suitable for structural and semi-structural applications such as lightweight partitions, wall and floor panels, and lightweight blocks. Cementitious foams derived from Allied's premium systems are suitable for thin layer coating applications where specific performance criteria are required.

Foamed concrete and foamed cement made with Allied's foam have very fine pore structure, unlike that made with conventional proteinaceous and surfactant foams. The pore structure of Allied's foams hardly show any sign of deterioration as the density of the foamed cement decreases to below 160 kg/m³ (10 pcf). At densities below 160 kg/m³, the pore texture of foamed cement derived from conventional foam agents becomes so coarse that most of them show severe structural collapse.

The dynamic nature of Allied foam systems allows different foam rheology to be incorporated into the host cement/concrete matrix to satisfy a wide range of slump loss requirements.

The inert nature of Allied foam systems makes them compatible with different kinds of aggregates, fillers, extenders, retarders, accelerators, colorants, hydraulic inorganics and many other additives.

Highlights on Allied’s WORK witH Geotechnical engineering, LANDSCAPE ARCHITECTURE AND SLOPED ROOF DECK

Composites with Allied’s premium foamed cement/high slump-loss/high strength 35 pcf foamed cement allows greater and simpler landscape architecture and roof deck designs not achievable by any conventional cellular concrete.

1. Geotechnical Engineering & Landscape architecture

A. conventional cellular concrete - conventional 35 pcf LDCC (Low Density Cellular Concrete) with shaved expanded polystyrene blocks.

Very limited slope negotiation for conventional cellular concrete – less than ½ inch drop per 10 feet span.

Geofoam/styrofoam blocks of various sizes/shapes are needed to create artificial slopes.

Labor intensive and slow process.

B. New and flexible designs with Allied’s 10 pcf premium foamed cement/35 pcf high slump-loss foamed cement

Highly sloped landscape with > 1 feet per 10 feet span can easily be achieved.

The use of Geofoam/styrofoam blocks is significantly reduced or totally eliminated.

Labor savings and faster process.

High Slump Loss Foamed Cement/Lightweight Aggregate Composites with Low Shrinkage at a Dry Density of 35-50 pcf (565 - 806 kg/m3)


> 2.5 feet drop per 10 feet span (1V/4H)	Full Size Air Conditioner Pad From High Slump Loss/Low Shrinkage Foamed Cement Composite
(dry density = 35 pcf)	(dry density = 48 pcf)

Field Application of High Slump Loss Foamed Cement Composite on Sloped Geofoam - Harvard University NorthWest Laboratories Project, Dec. 2007 completed.

(Pre-project mockup work is shown below)


Mixing & Pumping of High	Applying of High Slump Loss	Finished Foamed Cement Crown	Cross-section of
Slump Loss Foamed Cement	Foamed Cement on 1V/4H Slope	On Highly Sloped Geofoam	Landscape after ~ 1 year

2. Improved Foamed Cement Roof Deck Designs

Highly sloped industrial and residential roofdecks or roofings become possible with Allied's high slump-loss foamed cement product and mix design.

Allied's stable foam with high slump loss can be applied directly on corrugated metal sheets of new or repaired roofs without foam dewatering and possible water leakage to the interior structure of the floors underneath while such problems have always been associated with conventional cellular concrete roof decks.

Using Allied’s 35pcf/10 pcf foamed cement composite as roof deck structure will achieve the right combination of thermal insulation and light weight like conventional cellular concrete/styrofoam blocks but with appreciable labor and time savings and the flexibility in roof deck designs with varied shapes and contours not achievable before.

Comparison of Roof Deck Composites from Allied's Foamed Cement Composite & Conventional Foamed Cement/Expanded Polystyrene Board Composite.

Allied's 35 pcf/10 pcf Foamed Cement Composite

Conventional 35 pcf Foamed Cement w. EPS Boards

lightweight roof deck,foamed concrete


A unique roof deck project using Allied's foam products and foam generating equipment is shown by a recently renovated sports field on the
roof of an existing gymnasium - 120,000 square foot coverage with
foamed cement pumped 3 stories high and 500 feet across the field
(the weight limit, compressive, shear and other performance demand and its
intended use made the project one of its kind in the US roof deck industry.)
Georgetown University Sportsfield, Washington D.C.
Foam Sytem - AFT-450 series at 40 pcf (645 kg/m³)
Roof condition before	Roof preparation	Material Setup	Equipment Setup

Pouring foam cement	Foam cement roofdeck	Turf application	Gym under the deck

Highlights on Allied’s WORK with Foamed Blocks and Foamed Panels

Autoclaved aerated concrete (AAC) was introduced in Europe over half a century ago as a lightweight construction material. The key features AAC has over conventional foamed concrete are significantly better strength and lower shrinkage/cracking. However, most of the attempts over the last few decades to introduce AAC to the US either failed or hardly made any signifcant impact to the construction industry. The million of dollars of capital investment needed for the manufacture of AAC over the conventional precast plant is just one of the many reasons reported in the literature.

Allied's stable foam products, low water/cement ratio with high range water reducer, and the synergistic use of various lightweight aggregates have allowed foamed concrete that matches the compressive strength of AAC with low shrinkage/cracking. A recent client claims that the use of Allied's foam products allows their lightweight precast outperform all others in the market.

Freshly prepared cement/aggregate bricks/blocks derived from Allied's specialty foams with high slump loss may even be extrudable and thus amenable for mass production. A freshly cast foam brick at 37 pcf (600 kg/m3) without using any mould is shown below:

Freshly Made Foam Cement Brick w. High Slump Loss (density = 37 pcf)	Extruded Foam Cement/Ltwt Aggregate Composite (density = 40 pcf, compressive strength = 660 psi (4.6 MPa))	Instantly Demolded Cement/Ltwt Aggregate Composite (density = 31 pcf, compressive strength = 460 psi (3.2 MPa))
(a mould-free cast)	(low pressure extrusion)	(demolded in < 1 minute)

a brief comparison of KEY PROPERTIES BETWEEN ALLIED'S FOAM/AGGREGATE COMPOSITE AND AAC IS GIVEN BELOW:

	Allied's Foam/Aggregate Composite	Autoclaved Aerated Concrete (AAC)
Compressive Strength (relative to conventional foamed concrete)	High	High
Shrinkage/Cracking (relative to conventional foamed concrete)	Low	Low
Water Absorption (relative to conventional foamed concrete)	Lowest in the industry	High (see the figure on lower right)
Window for Concrete Processing Additives	Compatible w. various concrete additives, processing aids and pigmentation	Mostly incompatible due to its aggressive steam curing condition
Foam Density Available	From 5 pcf to > 90 pcf	Mostly in the 30 to 50 pcf range (due to the limitation in its foaming process & steam curing efficiency)
Method of Production	Precast, cast-in-place & extrusion (with specific mix design & slump loss)	Precast only
Capital Investment	Similar to a conventional precast plant	Millions of $ over a conventional precast plant

STRENGTH & WATER RESISTANCE PROFILE AT 30 - 60 PCF (480 - 970 Kg/M³) - Loadbearing (low rise), semi-structural & non-loadbearing.

lightweight concrete,foamed concrete

28 DAYS STRENGTH PROFILE AT 55 - 80 PCF (890 - 1,290 Kg/M³) - loadbearing andsemi-structural.

(The following data are derived from mix designs that may have different slump loss characteristics from that at 30 - 60 pcf)

Density (Air Dry)		Compressive Strength
(pcf)	(Kg/M³)	(psi)	(MPa)
56	900	1,200	8.2
65	1,040	1,480	10.2
69	1,110	1,700	11.7
74	1,190	2,300	15.9
76	1,240	> 2,500	> 17.2

COMPOSITES AT 10 - 20 PCF (160 - 320 Kg/M³) - non-loadbearing & insulative.

Even at densities as low as 10 pcf, the strength development of Allied's foam/lightweight aggregate composites allows <24 hours demolding time while still maintaining good handling characteristics (all three blocks shown below were demolded in 18-24 hours and were immediately saw-cut to proper size)

10 pcf (160 Kg/M³) 15 pcf (240 Kg/M³) 18 pcf (290 Kg/M³)

Panels and Blocks Based on Allied's Foam & Lightweight Aggregate Mixes


45 pcf 36 pcf 46 pcf	Cross Seection of Foam/Aggregate Panel

Foam/Aggregate Blocks 35-45 pcf (565 - 726 Kg/M3)

PERFORMANCE

Some Performance Features of Concrete and Cement Incorporating Allied's Foam Systems:

Consistent and fine pore texture at different densities

Low water uptake

Hight early and 28 day compressive strengths

Good thermal and acoustic properties

Wide range of rheological, adhesive and thin-set properties

24 HOURS STRENGTH DEVELOPMENT OF AFT FOAMED CEMENT IN VARIOUS MIXES

FOAMED LIGHTWEIGHT CONCRETE

Lightweight Concrete	Lightweight Concrete	Lightweight Concrete	Lightweight Concrete	Lightweight Concrete
Roof deck,	Wall Partition	Block Inserts	Blocks	Wall & Floor Panels
Geotechnical Engineering & Landscape Architecture

		Foamed Cement Cylinder	Foamed Cement Cylinder
Foamed Concrete (density=75 pcf)	Foamed Concrete (density=75 pcf)	(density=30 pcf) Allied AFT-400	(density=30 pcf) Proteinaceous Foam
		(high early strength cement formulation)	(high early strength cement formulation)
Allied AFT-300	Proteinaceous Foam	no foam collapse	severe foam collapse
uniform & fine texture	non-uniform & coarse texture			collapsed foam

Please activate Java...
	FOAM CERAMICS LANDFILL COVER
	FOAM ADHESIVE, COATING, FIREFIGHTING FOAM