Advanced Cement Composites


(Wilfried Ellmer) #21

In the context of “building technology”… | bonder component in cement based composite materials | portland cement | roman cement | geopolymer concrete | construction technology |


Al-tobermorite


Making concrete better

The best traditional Portland based concretes have median lifetimes on the order of decades - and this is usually with significant overhauls and regular maintenance with modern epoxy fillers. Nothing built today will last for the ages. Yet over two thousand years ago the ancient Romans managed to create a concrete mix that has stood the test of time. The Pantheon, originally built as a temple to the Gods, has an unreinforced concrete dome which spans 142 feet and has lasted for over 1800 years. Similarly, concrete Roman harbor structures exist which have been submerged in seawater for over 2000 years and are actually stronger now than when they were first constructed. How is this possible? Recent research at UC Berkeley in conjunction with Lawrence Livermore National Laboratories has shown using nuclear imaging techniques that Roman cement contains an extremely rare mineral called Al-tobermorite. This mineral forms when the cement is exposed to seawater and active ion exchange takes place. The precise reasons why this occurs are complex but stem ultimately from the volcanic pozzolanic material used as part of the mix design. Tobermorite forms fine reinforcing mineral threads which continue to grow and strengthen the cement as it ages, and even “heal” the cement across micro-fractures.


| http://nautilusmakercom/t/al-tobermorite-concrete-submarine/4576


Our group is currently handling, investigating, and testing, a list of about 200 materials among fiber, filler and bonder components in the development pipeline…


context | Floating Concrete Building Methods | Floating Homes Caribbean USD 98K Budget |



(noboxes) #22

However, it is not monolithic, and is surprisingly unsubstancial, containg voids and blocks of pumice. The pumice is so light it can float on water, and so fragile it has been uses in soaps.


(George Hawirko) #23

Time here to add the Structure of Polystyrene EPS Foam. Already available and almost indestructible in all conditions when skinned with Polymer Concrete. image


(Wilfried Ellmer) #24

@EPSComposite

George, in the context of “Advanced Cement Bonded Composite Materials” Polystyrene Foam is one of those 200 materials ( bonders, fibers, and fillers ) that we have investigated in our group.

It can be used as a light filler material in many applications.


context | advanced cement bonded composite materials | bonders | : Roman Cement Bonder Composites • aluminium tobermorite • phillipsite


context: It is the nature of a composite material, which consistis of | bonder | fiber | filler | components that the properties of the structure is only very indirect tied to the properties of the materials it is made of
... assuming that a glassfiber composite yacht is a "boat of fragile glass" or a carbon fiber piece is a "piece of crumbling coal" is just a concept error and a lack of understanding of the technology of composite materials ...
Components that have unimpressive strength by themselfs can develop impressing strength in a composite material - it depends on the builders ability to get it right - not on the materials.
The very idea of a composite is that each material covers the weakness of the other materials ... it is a kind of group effort...that creates new properties.

#25

Not true.

Unless reinforced with rebar, it will collapse in 15 feet seas. Even reinforced, EPS would make a very poor application for a seastead’s “hull”.

What’s the point of EPS flotation as an unused cubic space when you can build a “hull” and use all the space down bellow?


(George Hawirko) #26

Sorry about that oversite in my post. wasn’t sure that I was to get into extream details. EPS Concrete composites might be a better term and it encompasses a huge range of applications and engineered parts. All this is exceptional information in the quests for Climate Change Survival, Seasteading and Space Expploration.


(George Hawirko) #27

Getting back to the EPS, in the range of 92-98% air you can save on Shipping Handling and Storage of the necessary basic building materials. You will also notice that the Cells can be replicated for the many othe Components needed during construction.


(George Hawirko) #28

Seasteading and Concrete go together for longterm quality Infrastructure. Composite Concrete comes in hundreds of variations and actually needs it’s very own Manuals. Composites need redefinitions and understanding, for example,

Ferrocement as I describe it leaves out the Ferro and substitutes the Cement with Concrete. Steel is best removed from Composite Concrete to reduce maintenance and weight.

Thin-Shell, Composite Concrete is strengthened when EPS (Expanded Polystyrene). Monolithic and Monocoque Floating Structures are possible in Super Sixes when using these techniques.


#29

If you “leave out” the ferro armature, there is no structural integrity support for that hull… Can’t do that.

“Best” for what? First, dito above. Second, there is no “maintenance” to perform to the the steel armature of a ferrocement boat. Third, reducing the weight of a seastead is overall detrimental to its stability and sea keeping abilities.


(Wilfried Ellmer) #30

Another interresting fiber / reinforcement / material in the context of saltwater resistent cement composites…


Check this study investigating the potential....

Potential of Carbon Nanotube Reinforced Cement Composites as Concrete Repair Material


Carbon nanotubes (CNTs) are a virtually ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. It is evident from contemporary research that utilization of CNT in producing new cement-based composite materials has a great potential. Consequently, possible practical application of CNT reinforced cementitious composites has immense prospect in the field of applied nanotechnology within construction industry. Several repair, retrofit, and strengthening techniques are currently available to enhance the integrity and durability of concrete structures with cracks and spalling, but applicability and/or reliability is/are often limited. Therefore, there is always a need for innovative high performing concrete repair materials with good mechanical, rheological, and durability properties. Considering the mechanical properties of carbon nanotubes (CNTs) and the test results of CNT reinforced cement composites, it is apparent that such composites could be used conveniently as concrete repair material. With this end in view, the applicability of multiwalled carbon nanotube (MWNT) reinforced cement composites as concrete repair material has been evaluated in this study in terms of setting time, bleeding, and bonding strength (slant shear) tests. It has been found that MWNT reinforced cement mortar has good prospective as concrete repair material since such composites exhibited desirable behavior in setting time, bleeding, and slant shear.


http://nautilusmaker.com/t/potential-of-carbon-nanotube-reinforced-cement-composites/4583

(George Hawirko) #31

All very important when considering the use of automated printing of Monolithic and or Monocoque Structure.


(George Hawirko) #32

Steel will always be a problem when thinking long-term, use of Composites, ie. Fiberglass, Polypropolyne to Carbon Fibers are used instead and allow for automated Construction of Hull and Components.

Weight reduction is very important for Storage and handling during Construction. If you continue using the term "FerroCemen"t you win this argument, I prefer to think of Concrete Composites and Monocoque Construction as the future we need to concentrate on.


#33

Not if built to high standards.

You mean instead of a steel armature? At what cost? Even so, you will have to prove that this new untested hull building process is far superior that the already proven old ferrocement one. Testing costs money…

Why? If a seastead will be built it will be either a small, medium or large one using either a continuous construction process (pour) or a modular construction. Regardless of which process, weight hasn’t much to do with it since an A x B x C seastead built of cardboard will have almost the same volume as one built of lead.

Since the same volume, the cost of renting an A x B building area in a boat yard will be the same.


(Wilfried Ellmer) #34

Interesting Topic in the context of Advanced Cement Composites


workhypothesis: down the road seasteads can obain their building material from the ocean…



The question of the source of the building material is of essence in the light of the asian sandwars limited supply is a potential severe problem on this scale.


Composite cement mortars based on marine sediments and oyster shell powder


(google it up)

context: floating cities-solving the technology bottleneck



(noboxes) #35

That may be true in your version of a seastead, but not mine. For one thing, any weight you add is something you bought and added to the seastead, and then had to make compensations somewhere to support that added weight.


#36

Wrong. “That” is true based on rigorous scientific fact: naval architecture, an exact science, irrelevant of anybody’s “version” of seastead.

I was talking about the total displacement of the seastead’s hull, ready to occupy and launch. What’s “added” is people, fuel, water, provisions, plus any other “cargo”.

Such “added cargo” is already compensated from the drawing board: seasteaders (visitors) quarters, water tanks, fuel tanks, provisions and other cargo holds (storage space). It’s all calculated, drawn-designed to specs and built to specs, and most importantly, when operated is managed to strictly enforce the stability letter of such seastead.

There is a lot of science that needs to be applied to seasteading in order to live @ sea indefinitely, says I.


(noboxes) #37

And that is your 20+ year concept of a thing that floats: a traditional hull that resembles a bathtub. That is not my idea of a seastead. Your idea uses the weight as a brute force to fight the waves and orient the bathtub upright. My idea doesn’t use brute force or live in the wave zone. To quote you: go see a shrink and get over it.


#38

Whatever rocks your seastead.

I did, and it’s all good. That’s why I highly recommended it to some of the people hanging around here.


(Wilfried Ellmer) #39

In the context of “advanced cement composites” and building material that is not “dependent on land based supply” consider the case of Basalt Rebar…basalt is abundant in the ocean - a civilization can be built on it …actually it is more economic and better suited for the oceanic environment than the currently used steel rebar - the only problem that holds it back is “code compliance” we can solve that issue.


Basalt Continous Fiber (BCF) especially useful for creating advanced cement bonded composite structures…


(noboxes) #40

Please explain where you will get the basalt. Please explain where you will get the huge amounts of energy used to dehydrate raw materials as dug from the ground, and convert it to portland cement.