Table of Contents
One of features of modern approach to low construction is material utilization with simple technology of mounting and the minimum heat transfer coefficient. Papercrete blocks: which price is available to all, meet these requirements completely. It is enough to tell that this building material repeatedly exceeds brick, slag stones and concrete on heat transfer coefficient, and concedes to wood only slightly.
What is wood concrete and its main properties
First of all, we will consider composition of wood concrete. Its basis includes the dried-up sawdust. At the same time certain requirements are imposed to spill for wood concrete.
Its particles have to have the needle form and fit into such sizes:
- width is from 10 to 12 mm;
- thickness is from 2 to 3 mm;
- length — not less than 15 and no more than 25 mm.
Spill mixes up with the cement knitting and other additives improving quality of the final product – papercrete blocks. At once on preparation of wood concrete (so professionals call the received mix), it spreads in forms and is condensed by means of vibrotable. After 30-40 hours at the following production phase of papercrete building material, these blocks are removed from forms and are placed on special site where they gain durability. On it it will be required up to 30 days. And only then this building material can be used.
Helpful advice! Creating wood concrete the hands in the form of blocks, lay them in wet state under film. Process of hydration at temperature of 15 °C lasting 10 day will give them the greatest possible durability.
Such technology allows to create papercrete blocks, different in the sizes. They can be both wall, and partition walls.
As for the specific size of masonry unit of this kind, the modern industry adheres by production of the following characteristics:
- height is from 20 to 25 cm;
- width is from 5 to 25 cm;
- length is no more than 60 cm.
Besides, also “complementary” products are issued. Proceeding from the name, it becomes clear that such papercrete blocks having the form of corners, halves and other “wrong” geometry allow to do without adjustment and cutting of normal elements. Thanks to such technical solution the buyer can pick up wood concrete building material of the most suitable configuration.
Let’s stop your attention to heat conductivity of wood concrete. It is useful for the people aiming to save as much as possible on construction of country cottage to know it. The house wall from papercrete blocks thickness equal of 20 cm, on heat transfer coefficient corresponds to brick wall of 1-meter thickness. Therefore in cold regions of our country expenses on warming of construction will be much less in comparison with use of brick.
One more essential advantage of blocks from sawdust and cement is their small weight. They for 80-90% consist of dry-through spill. For this reason bearing capacity of the base can be approximately same, as well as for timber structure.
Comparison of characteristics of blocks from wood concrete with others construction to materials
To understand whether is suitable for construction papercrete blocks, it is worth making comparative analysis of properties of the most popular building materials.
Comparison of properties of wood concrete, bar, foam mortar and brick:
|Material properties||Brick||Cellular concrete||Wooden bar||Wood concrete|
|Degree of complexity of fastening of house design to wall||Special fixture||The expensive special fixture calculated for work with fragile material||Perfectly fastens screws, nails, normal dowels||Excellent fastening by screws, nails, normal dowels|
|Term of construction and commissioning||Long and expensive process as warming and finishing||Fast wall construction is required. A lot of time leaves on outside warming of facade. It is process labor-consuming and expensive||Because of shrinkage of material after incident of year after construction carrying out finishing work will be required||Fast wall construction, additional warming is not required, it is possible to carry out finishing at once|
|Base cost||Expensive, massive||Expensive massive monolithic continuous footing||Economic, easy||Facilitated, economic|
|House microclimate||The organization of mechanical ventilation of the room will be required||Weakly Breathable||Removes the increased humidity, breathes||Removes the increased humidity, breathes|
|Firmness on bend||Brittle, does not work for bend||It is deprived of plasticity, brittle, gives massive cracks at fluctuations of the base, badly transfers transportation||Well works for bend||Well works for bend, does not burst at fluctuations of the base, transfers transportation perfectly|
|Bioproofness||Biostable||Biostable||Decays||5 group of bioproofness|
|Fire resistance||Not combustible material||Not combustible material||Easily ignites||Fire does not support|
|Heat conductivity, Watt / (м× °C)||0.560-0.850||0.140-0.320||0.150||0.07-0.17|
|Density, kg/m ³||1150-1950||200-1200||450-600||400-850|
The vapor permeability of blocks from wood concrete is only a little less indicator of wood. Thanks to this property in houses from wood concrete humidity level always optimum. Durability of papercrete blocks does not depend on extent of absorption and evaporation of moisture therefore by its transfer walls do not collapse.
Helpful advice! When choosing products, pay attention to the parties of products. If one their end face smooth, and all others significantly differ from it, it is better to refuse purchase of the offered party as this sign indicates that production technique of wood concrete has been violated, and cement has simply flown down down.
Extent of drying of sawdust has significant effect on quality of wood concrete. If only dry spill was used, then the size of internal humidity of blocks will never become critical therefore to the wall which is put up from them frosts will not be terrible. When wet sawdust was used, it is possible that in several winters wood concrete will begin to lose durability. At negative temperatures water will freeze, increasing at the same time in volume that leads, in turn, to destruction of the knitting component.
From other practical properties of this material it is worth allocating:
- loads of stretching are not terrible;
- resistance to mold and decay;
- is not afraid of fire.
Thanks to the last property degree of fire danger of papercrete houses is closer to this indicator of stone and brick buildings, than timber structures. However, if large-scale ignition happens in construction, or it will appear in zone of heavy fire, walls will lose considerable part of durability. Steel concrete, stone and brick what you will not tell about other types of lightweight-aggregate concrete are to a lesser extent predisposed to such effects.
Papercrete blocks, piece price of the most demanded types
The modern industry produces two types of wood concrete – constructional and heat-insulating. Material of the second type is not used at construction of external and internal walls as it is characterized by rather small density and rather small weight. It with success is applied to warming of buildings, residential buildings, brick-built, claydite and also other construction elements.
Blocks of constructional type are necessary for creation of load bearing walls. Their strength indices and density are higher, than at similar products from heat-insulating wood concrete.
Comparative characteristics of heat-insulating and constructional wood concrete:
|Wood concrete type||Application in construction||Strength class at compression||Durability, kg/CBM||Density, kg/CBM|
|Heat-insulating||Warming of walls||In 0.35-1.5||M5, M10, M15||400-500|
|Constructional||Construction of load bearing walls||B1.5-B3.5||M25, M35, M50||500-700|
Papercrete blocks of the following types belong to the most popular types of these products:
- big products from wood concrete. They are used for laying of the walls which are exposed to loadings. The sizes of samples — 500×300×200 mm. They are marked so: D500, D600;
- small papercrete blocks. Are mainly used for making of insulating ranks and for construction of not bearing easy walls. The block size — 190×190×300 mm. Brands – D500, D600.
Papercrete blocks: the price depending on scope of application
The cost of the considered products is influenced also by for what it is used and also configuration of single product.
Helpful advice! Buy papercrete blocks on which surface there is no white raid. It is the evidence of addition of glue that on technology it is not allowed.
Features of structure of papercrete blocks
The main components of wood concrete are the fillers, chemical additives mineral knitting water.
Function of organic additives is performed:
- woodworking waste (pine, fir, poplar, fir-tree, aspen, beech, birch);
- raw materials processing waste – fire linen or hempy;
- stalks of rice straw, cotton.
Wood material, in particular, sawdust with shaving (1:1, 1:2), sawdust with shaving and spill (1:1:1), shaving, spill is among the most demanded filler. The above-stated proportions of filler in wood concrete are accepted on volume, but not on weight. Usually those who are engaged in production of masonry units in the hands as unit of measure use standard bucket. For example, the proportion of papercrete components 1:2 is understood as 2 buckets of shaving and one bucket of sawdust. Instead of the last ingredient the fire of flax can use or hemp stalks.
Requirements to filler are formulated so:
- concentration of impurity of bark in the crushed raw materials should not exceed 5% of needles and 10% of leaves;
- particles should not be too small. Otherwise the bigger consumption of cement will be required.
The main lack of material – its chemical activity.
Pay attention! By preparation of batch use of larch and freshly-cut wood of one and all breeds is not allowed.
Fire of flax is full-fledged filler, but only at observance of the following production requirements:
- length of particles is no more than 40 mm;
- obligation of introduction of chemical additives because of availability as a part of sugars;
- for the purpose of improvement of quality of wood concrete, the production process includes the procedure of processing of material limy milk (50 kg of lime on 200 kg of this filler);
- after processing before introduction to batch of fire it is maintained up to 2 days.
Such technology allows to reduce portland cement expense up to 100 kg on 1 cubic meter of wood concrete. Also there is one more requirement: in raw materials there have to be no signs of mold and decay, foreign debris. If works on production of papercrete blocks are conducted during winter time, it is necessary to control availability in filler of ice and snow. At stage of preparation of raw materials it is necessary to get rid of such inclusions.
Helpful advice! Upon purchase test products. Acquire only that party which of samples to pick out spill hands it will not turn out. It is sign of good adhesion.
Chemical additives are entered for ensuring compliance and perform the following functions:
- accelerate hardening;
- regulate porosity degree;
- slow down corrosion;
- give to the final product high bactericidal and insecticidal properties.
Use of additives is recommended irrespective of for what climatic zones of our country projects of houses from papercrete blocks have been developed – beginning from Arctic and finishing subtropical. In addition, special chemical additives provide improvement of quality of products at the expense of possibility of use of filler without preliminary endurance.
As additives are applied:
- sulfate aluminum;
- slaked lime;
- chloride calcium;
- liquid glass.
Optimum additives it is considered to be chloride calcium and sulfate aluminum. Application of the last connection allows to increase durability of wood concrete. It is caused by what aluminum reacts with sugars and, neutralizing them, transfers to harmless state.
The amount of additives in papercrete blocks from the producer, does not exceed usually 2-4%. In absolute values it makes about 12 kg on 1 cubic meter of wood concrete. Both options of use of additives – in a complex or separately are allowed.
Their proportional ratio is defined by the required branded durability of wood concrete.
So, for example, wood concrete of M30 brand may contain the following combinations of additives:
- aluminum chloride (AlCl3) and calcium chloride (CaCl2) of 4% of weight of the used cement in the ratio 1:1;
- aluminum sulfate (Al2(SO4)3) and calcium chloride — the same proportions;
- sodium sulfate (Na2SO4) and aluminum of chloride 2% of cement weight, ratio 1:1;
- aluminum chloride and sulfate of sodium (Na2SO4) of 4% of the total weight of cement in the ratio 1:1.
Sizes of papercrete plates
The distinctive feature of these products from blocks from wood concrete is displayed in their name. The concept “plate” means that thickness of unit of similar products is much less than other its sizes – lengths and width.
For their production the processed wood spill and binding component – cement is also used. Production of cloths is carried out by way of tamper and pressing. In comparison with process of production of plates of all brands of lightweight-aggregate concrete on release of such products wood concrete is left by much less time (vibropressing duration – only 20 sec.). That products have gained branded durability, leave them for several days indoors with strictly measured temperature condition.
Helpful advice! For providing long life cycle of wood wool cement slabs, it is necessary to execute their external and interior finish as soon as possible.
Now wood wool cement slabs are issued the following sizes (measuring unit – centimeters):
- wall cloth (these are the biggest panels) — 28×118×229, 30/40×118×230;
- narrow cloths (products for upper crossing points) — 28×58×229, 30/40×60×230;
- window panels — 28×58×81, 28×118×81 and 30/40×118×80;
- ordinary peremychny blocks — 28×178×58;
- the strengthened peremychny blocks — 28×238×58.
In the course of production of the outside cloths equipped with fixing reinforcing loops they become covered by “draft” facing layer at once. This layer consists of cement and sand plaster, and its thickness is equal to 150 mm. Such technical solution allows to save to the customer on external finishing.
Production of papercrete blocks the hands
Production in house conditions of wood concrete attracts with possibility of purchase of the necessary materials at the low price. But it will be for this purpose necessary to organize some kind of mini-plant with the different equipment for production of papercrete blocks. In principle, it is possible not to buy the necessary devices, and to lease: though it is hard to find them, but thanks to the Internet it is possible.
We already know that papercrete blocks are such building material for which production it is necessary to use certain components. Their list is stated above, and here we will consider proportions further.
Proportions of ingredients in one cubic meter of wood concrete:
|Wood concrete grade||Water, l||Chemical additives, kg||Organic filler, kg||Cement, kg|
|M25. Constructional wood concrete||350-400||12||240-300||300-330|
|M15. Heat-insulating wood concrete||350-400||12||240-300||250-280|
In practice when at hand there are no corresponding measuring tools – scales and measured tanks — professionals recommend to use the following formula: 1 cubic meter of wood concrete = 4 parts of water + 3 parts of spill +3 parts of cement. The amount of chemical additives remains the same — 12 kg. For determination of the necessary weight it is necessary to be guided by the digits which are present at their packaging.
What is required the equipment and the general technique of production
In that case, so far as concerns bulk production of building material of the considered type (for example, at construction of houses in the cottage settlement) for production of papercrete blocks it is impossible to do without machine. It is possible to find samples of such equipment in sale with productivity up to 40 products an hour.
If it is going to manufacture papercrete blocks for ensuring construction of one owner-occupied dwelling, it will be necessary to get the following devices:
- capacity for mix;
- the catcher for chips;
- the giving table;
- the shock stirring-up table;
- inserts in form;
- metal pallet of form;
- connector form;
- vibroforming installation.
For production of form use normal wooden boxes. From within them upholster with linoleum. Wood concrete is put in form layer-by-layer. It is necessary to do it in 2-3 calling. After bookmark each layer is carefully stamped.
Helpful advice! For removal from the mass of excesses of air and moisture pierce it armature. It will increase durability of the final product.
The last layer is not smoothed, left uneven. It should not reach edges of boards on 2 cm. This space will be filled with finishing mortar. It is recommended to maintain the block in shape not less than 24 hours.
That it is better: wood concrete or gas concrete
To answer this question, it is necessary to compare properties of both materials.
Comparison of properties of wood concrete and gas concrete:
|Parameters of blocks||Wood concrete||Gas concrete||Comments|
|Standard characteristics for load bearing walls||200×300×500 (mm)||250×375×625 (mm)||Walls of the house and wood block are colder as thickness of element is less|
|Error of the sizes, +/-mm||5||1||Availability on the surface of papercrete blocks of roughnesses complicates alignment of walls that, in turn, causes increase in consumption of material and education between masonry seams of “cold pipe rack”|
|Fire resistance, hour||From 0.75 to 1.5||3-7||Wood block is less steady against influence of high temperatures|
|Shrinkage (mm on m)||0.4-0.5||0.35-0.46||Natural filler is characterized by higher rate of shrinkage|
|Elastic modulus, MPa||250-2300||Of 1734||Papercrete block maintains loadings better|
|Water absorption, %||40-85||<15||Moisture absorption wood blocks is promoted by availability in its composition of vegetable filler. Therefore wood concrete demands reliable are sewn up|
|Coefficient of thermal conductivity of the blocks which are in dry state, W/m ²||0.08-0.17||0.072-0.14||Heat insulation of gas concrete is higher|
|Average density, kg/cubic meter||500-850||300-600||Papercrete blocks create heavy load on the base|
|Frost resistance, cycle||25-50||35-50||Products from gas concrete have the bigger term of operation|
There is also one more important criterion – convenience of facing. Judging by responses, papercrete blocks are won in this plan against products from gas concrete. They do not crumble at mechanical influence. Therefore the panel can fix, using normal anchors.
Some features of construction of bath from wood concrete
Cost value of construction of bath from this material same, as well as at assembly of the building from log or wooden bar. However use of wood concrete in laying of walls gives ample opportunities in design and finishing both outside, and from within. The internal covering can be made of standard “bathing” material – eurolining or block house. And use of ceramic tile allows to create interesting effect by entering into interior of the room of the color gamma corresponding it to functionality. Finishing of external walls can be any, beginning from usual block house under the rounded bar and finishing with log.
But anyway it is necessary to consider hygroscopicity of wood concrete. That is walls of bath have to be carefully covered from dampness.
Helpful advice! From within construction should be sheathed with vapor barrier, leaving free space between interior finish and blocks. Outside it is possible to plaster or impose with decorative brick.
Papercrete blocks: responses of owners of houses, minuses
Choosing building material for construction of the house, useful will be to listen to responses of the house masters having practical skills in this sphere. Unlike advertizing slogans of the manufacturing plants, their opinion – objective. Besides, there is one more moment concerning including, papercrete blocks: responses of owners of houses contain information on what mistakes have been made by them at construction of buildings from this building material. So, having got acquainted with them, you will be able to save not only time, but also money.
The easiest to carry out the analysis of shortcomings of wood concrete on posts at Internet forums of construction subject. Excerpts from some messages are given below.
“Work with wood concrete is continuous punishment. The deviation of the sizes sometimes reaches 20 mm! It was necessary to provide plain surface of wall to spend a lot of time. For completion of works it is forced to invite builders”.
“Instead of the promised smell of wood and healthy microclimate in the house the smell of chemistry of some unclear origin is caught. According to specialists of construction company – all this because of the additives entering wood concrete. The question concerning whether it will be eliminated after finishing or just will disappear, remains over time open”.
These two posts are not connected with types of products from wood concrete. And ignorance of features of use of this building material often also causes emergence of negative reviews. Papercrete blocks as it has been told above, happen, constructional and heat-insulating type. If not to see between them difference, it will be possible to receive at all not that result which the owner expected.
“We live in the cold house from wood concrete the third year. Warming initially was not planned. But, apparently, it will not be possible to do without it. For construction of the strong two-storeyed house with penthouse I used constructional blocks from wood concrete. Hoped, as so the house will be warm. Most likely it will be necessary to spend in addition for its warming by heat-insulating wood concrete or some other material”.
Having studied information on properties of papercrete blocks and also responses of users, it is possible to pick up the most suitable for the size and cost option for construction of the house or bath.