CN105220818A - A kind of husk dry method modification manufacturing module green building material also builds the new method in house - Google Patents

Abstract

The present invention is one husk is primary raw material, and by dry method modification, manufacturing module green building material also builds the new method in house.Patent 201210080798.6 is modified as the new fibriilar technology of basic raw material-improved plant vegetable material (agriculture and forestry organic waste material) by dry method and wet method two kinds of methods.The present invention is the dryness modification technology by this patent, uses the embody rule scheme that husk is raw material.Content comprises the formula carrying out modification with husk, the material Reaction extrusion method prepared is made green building material modular connecting elements section bar, makes large plate, large plate and connector are assembled into the technology of highrise building interior wall and low-rise building with hot pressing formation process.

Description

A kind of husk dry method modification manufacturing module green building material also builds the new method in house

One, technical field:

The present invention relates to husk is primary raw material, and dry method modification manufacturing module green building material also builds the new method in house.

Two, technical background:

Husk is the byproduct that in Rice producing, quantity is maximum, accounts for 20% of paddy by weight.China's rice yield 1.72 hundred million tons in 2014, produce about 3,400 ten thousand tons, husk per year, quantity is very large.But the domain variability that can use and consume husk at present is in a large number few, and maximum purposes makes fuel, but its calorific value only has 50% of standard coal, while a small amount of energy of acquisition, really release a large amount of carbon dioxide, all uneconomical on both macro and micro.Doing active carbon, cement, disposable tableware, building, packaging material etc. with husk has people to study, but is all difficult to industrialization, commercialization.As far back as nineteen fifty-one, Britain is just mixed and made into husk plate with thermosetting phenolic resin and husk, but due to poor performance, cost is high, fails to draw attention.After this U.S., Canada etc. last century the seventies produced a complete set of equipment and sold for China, in fact and immature, also have many problems to solve so far.After this ground such as China Zhejiang, Jiangxi have developed the production line of many annual output 5000 cubic meter husk plates supporting with 30,000 tons of Rice producing factories, and the husk plate made can only be used for packaging, furniture, owing to not having advantage in cost performance, does not produce market clout.

Husk is different from general stalk, and it contains the silica of 20%, and well-done texture material is hard, and density is light, and have good toughness, pest-resistant, corrosion resistant, thermal conductivity is low, and elasticity is strong, and optimum does green building material, for building house.Definition according to international material Science Research Association proposes for 1988: green building material adopts process for cleanly preparing and technology; use no or little natural resources and the energy of shortage; a large amount of use agricultural or municipal solid waste produce nonhazardous, pollution-free, "dead" (radioactive level is low); after reaching application life; can recycling, be conducive to the constructional materials of environmental protection and health.The present invention is primary raw material with the husk belonging to plant refuse, with clearer production technology, produces nontoxic, free of contamination Xylon polymerized composite material (polymerization wood); The modularization section bar of suitable rural house and urban skyscraper interior wall is produced with polymerization wood; With the mode of modularization profile material assembling, assembling urban architecture interior wall and rural house, both not large-scale construction equipment construction, also can replace brick and tile and part reinforcing bar, cement, build moderately well-off house, adapted to the situation fundamentally improving town and country habitat condition.With after can all reclaim, recycling, do not produce solid waste, meet the standard of green building material completely.At present due to the promotion of earth brick and tile price, use this green building material to do the interior wall ratio cement of urban house, the expense of fragment of brick is low by more than 30%, have very large superiority of effectiveness.The good period utilizing husk to do green building material arrives.

No. CN201210080798.6, patent of invention " plant modification fibrillation and manufacturing process thereof " proposes technology path vegetable material being carried out to modification, and proposes the manufacture method of " the improved plant fibrillation of production inflexibility structural meterials ".The present invention be directed to this specified plant raw material of husk, realize a concrete scheme of the dry method modification method that this patent proposes.

Three, summary of the invention:

(1) formula Design: husk is a special kinds in agricultural stalk.Its particularity is just the cellulose except containing 30% in its composition, the lignin of 20%, outside the hemicellulose of 20%, also contains the silica of 20%.For this special constituent structure, we select fine particle calcium carbonate to be one of base material.Become calcium oxide with calcium carbonate decomposed under the high temperature of hot pressing, condition of high voltage extruding, following modified-reaction occur:

CAO+H2O＝CA(OH)2

2CA(OH)2+SIO2＝CA2SIO3+H2O

The calcium silicates generated, can play adhesive.Except above-mentioned reaction, also added a small amount of MDI (diphenylmethane diisocyanate fat), modification occurs for it and SIO2 can generate PU/SIO2 composite material.Add the PVC having done stable process on a small quantity, their SIO2, MDI, modified-reaction occurs, generate PU/SIO2/PVC composite material.A small amount of THPC (or dihydroxymethyl phosphonium hydroxide) is added in formula, net structure can be formed with the cellulose in husk in modification, generate methene key and P-C-N key, while making green building material high flame retardant, also strengthen its intensity, more outstanding advantage is that it can stop pvc to decompose, and prevents it from giving off poisonous gas, the two synergy, can make building materials reach the flame retardant level not firing level.The maximum feature of formula Design is added with when producing improved plant fibrillation by patent 201210080798.6, with the natural polymer mixture that natural plants macromolecule extractant extracts in sewage, as the reinforcing agent and the sliding agent that add man-hour, the use for sewage extract have found the outlet that a high benefit utilizes.The material of this formula composition, in process, can react by the technology path generation polymeric composite of patent 201210080798.6, generate new material of good performance.

One of above-mentioned formula preferably proportionate relationship be, husk: calcium carbonate: MDI: sewage extract: PVC: THPC (dihydroxymethyl phosphonium hydroxide)=40%: 30%; 5%: 13%:10%: 2%.The building materials intensity produced of this formula is fine, and cost is lower, and fire-retardant, the energy-saving and environmental protection of modern housing need, livable, level of comfort is different, will be met different requirements by the formula of adjustment material.

(2) design of module die and profile material assembling.Green building material is designed to modularization section bar by the present invention.Prefabricated block component is divided into wall body construction, roofing element, ground member.By house floor height and load-bearing requirements, according to relevant national standard, with suitable reinforced concrete frame or imperial frame, with prefabricated green building material model calling framework, imperial frame, be assembled into room.Except large plate, all modularizing members have the mould of autonomous Design, realize continuous seepage by mould molding mode.

The green building material 80% in house is used on body of wall.Wall body module of the present invention is made up of large plate and connector (comprise edge sealing as Fig. 1 Fig. 2, lateral direct type material is as Fig. 3, and door sleeve is as Fig. 4, and 90 ° of corner pieces are as Fig. 5, and splicing bar is as Fig. 6, and I bar is as Fig. 7).Roofing is made up of girder steel, the large plate of roof structure, waterproofing course, isolation layer, roofing decorative board.These components are all shaped to standardized module prefabricated component in the factory, as long as user is assembled by figure.Wall big slab has individual layer slab and double-layer plate two kinds of structures.Example is installed as with doubling plate, first double-deck edge sealing (Fig. 1) is fixed on ground or metope, by in two pieces of parallel insertion edge sealed slots of the large plate of bilayer, in two grooves of the other end parallel insertion lateral direct type material (Fig. 3) of large plate, in two grooves of the other end of lateral direct type material, insert another two blocks of large plates ... .. is until corner.On the corner two blocks of large plates are inserted in 90 degree of corner pieces (Fig. 5), two grooves, insert another two blocks of large plates in the vertical channel of corner pieces vertical with last side's wall.There is piece groove the centre of lateral direct type material, by splicing bar (Fig. 6) insertion groove.I bar (Fig. 7) is used to be positioned in the middle of two blocks of large plates, reinforcing wall.Form three hollow spaces during two pieces of hollow large plate splicings and play sound insulation, heat insulation effect.Middle space can filling-modified plant fibrillation.Door sleeve (Fig. 4) is used to do doorframe.Use installation and the main distinction of the large plate of bilayer of the large plate of individual layer are relevant connectors is single groove structure, in each groove, only pacify one block of large plate.

The one-storey house in villages and small towns or low-rise building construction will by the design standard requirements of country, and lay bricks with reinforced concrete or cement and make column dragon frame, the design and installation of body of wall are identical with said method.The design on roof is; the imperial frame of wall connecting connects and takes part in Beam; Beam to mat formation large plate; as deck, in large plate, load improved plant fibrillation, form insulation layer, isolation layer, separation layer; pressing plate is made with one deck book plate; at pressing plate upper berth double-sided self-adhesive waterproof coiled materials, as waterproofing course, the tile fragment shape precast plate repaved with improved plant fibrillation is base material is protected and decorative layer.

Modularization section bar assembled house, can accomplish that component is few, and connect fast, operation is easy, and mould shape is relatively stable.Do not need large-scale construction equipment and specialized team's construction.

(3) technological design of connecting piece profile manufacture:

1, husk pretreatment:

The husk of moisture about 15%, calcium carbonate, polyvinyl chloride, sewage extract, other auxiliary agent are added in mixing roll and mixes, make and stand-by the material that modified-reaction generates polymer composite material can occur.Manufacturing large plate just directly uses this material to mat formation into slab.Manufacture connecting piece profile the material of mixing to be dropped in the hopper of abrasive particle machine, start abrasive particle machine, raw material rolls by abrasive particle machine emery wheel, is pulverized, initial reaction, generates particle, throws away from sieve aperture.

2, connector modularization section bar is manufactured with reactive modification extrusion molding:

Manufacturing composite member module section bar is adopt the extruder by modification requirement transformation, and the method for carrying out reactive modification extrusion molding manufactures.By the speed of Modification design requirement, pellet is added the hopper of extruder, after start, fall on screw rod, bitten by screw flight.Along with the rotation of screw rod is advanced toward heading forcibly by screw thread, the degree reduced gradually by the modification requirement design screw flight degree of depth and length, by the requirement of modification, the resistance that filter screen, flow distribution plate and extrusion die etc. produce is controlled, allow raw material in the process of moving ahead, form the pressure of appropriateness, material compacting, increase its heat conductivity, material is progressively plastified, the air existed in material is discharged.Be equipped with suitable heating system, make material while pressure raises, material is on the one hand by heating system heats, on the other hand because self is by the heat energy of the shearing of screw rod drive generation, compression, stirring movement generation, thus the transformation of experience glassy state---elastomeric state---viscous state, until melting., there is main reactive modification in the material of melting.After obtaining modification requirement, the material of melting is under the effect of screw rod thrust, be timed, quantitatively, enter the mould of connector equably continuously across merging core, the diameter of merging core will design by the character of material, the section bar of extrusion molding in mould, then shapes through fixed slot, cooling, tractor is drawn, and cutting machine cuts off, and has just made the connector modularization section bar that we need.

3, take husk as the manufacture of for building large plate of base material: large plate manufactures by the method that the hot press meeting modification requirement is shaping, and its flow process is:

1), the mating formation of slab.Select applicable spreading machine (Fig. 8-1), the material to be modified be stirred by the swing of feed arrangement, continuously trickle down in feed bin, and fall equably at feed bin width, little by little pile up, under the rake material of claw device rake teeth, be full of feed bin gradually.Feed bin belt delivers to throwing roller arrangement material dosing, enters shaped device by forcing to shed.Have in shaped device and throw the material casting of dress head, dropping on foraminous conveyer (Fig. 8-2) under suction function fast, by putting down, forming slab that is certain thickness, even density.

2), precompressed, preheating: the short texture completed through spreading machine, is full of the slab of air, by precompressed preheating machine (Fig. 8-3) precompressed, to make slab closely knit, has certain bearing strength, prevents fracture or slack.Can slab thickness be reduced after pressure, reduce the platen gap of hot press (Fig. 8-11), shorten plungers length, reduce press height.When also can prevent hot press from closing, air fills and damages slab edge.Precompressed preheating machine (Fig. 8-3) slowly reduces slab thickness at the less inclination angle of boot segment; In pressurized segment, by hydraulic pressure intensified pressure gradually; Pressure a period of time is kept, to reduce slab resilience in pressurize section; At Duan Youyi the small inclination slowly opened of leaving away, to leave away through the slab of precompressed.The hot air when bed board, uses hot plate precompressed when precompressed, keep upper plate 75 DEG C, lower plate 80 DEG C, to slab preheating, to improve its basal temperature, shortens hot pressing time, improves the quality of products.Preload pressure 1.8-2.0mpa, squeeze time 30-60 second.

3), hot pressing: with flat multi-daylight press (Fig. 8-11), at the temperature of 140 DEG C-160 DEG C, under the pressure of 3.5-5.5mpa, by contact-high frequency associating periodic heat method, slab directly contacts with heating panel, allows it be in high-frequency electric field simultaneously, is hot pressed into plate.Hot pressing is discontinuous, and one-period comprises dress plate, closed, boosting, pressurize, step-down, unloads the plate time.Pressurize and unload plate and all divide three sections to carry out, in case the generation of the problem such as bulge, layering, soft, warpage.Press has simultaneous opening and closing device.Thickness of compressive plate must meet the needs of walls and roofs design.Deep fat is adopted to be the thermal medium conducting heat energy.

4, the conveying of slab and backing plate: the conveying of slab and backing plate is technical very strong link, is related to the automaticity of production line.Slab conveying has backing plate and without backing plate two kinds of modes.Backing plate is had to carry point four sections of operations (see Fig. 8-1-20):

First paragraph: material is mated formation in transport guipure (Fig. 8-2) by spreading machine (Fig. 8-1) equably, sends into precompressed preheating machine (Fig. 8-3) and carries out precompressed preheating.After precompressed preheating, the drive motors of precompressed preheating machine drives the synchronously section of transport (Fig. 8-4), slab is transported to briar (Fig. 8-5), slab is cut into certain length.Enter and accelerate transport section (Fig. 8-6).

Second segment is for accelerating transport section (Fig. 8-6), and this section provides motor for oneself, and before slab does not enter this section, providing motor for oneself does not work, and is run by the driven by motor of the last period.After the slab be truncated all enters this section, touch travel switch, provide electric motor starting for oneself, this section is run fast, pulls open a segment distance with slab below.After slab departs from accelerating sections, touch again another travel switch, provide motor for oneself and quit work, this section returns to original speed.Go to meet another block slab.

3rd section is constant speed transport section (Fig. 8-7).This section provides drive motors for oneself, and its effect makes this section identical with the speed of accelerating to transport section (Fig. 8-6), can realize being interrupted conveying, be beneficial to equipped backing plate and slab.

4th section for joining backing plate section (Fig. 8-8).The task of this section installs on backing plate by slab, and it is connected with backing plate loop back device, and when slab enters this section of entrance, if empty backing plate does not arrive matching board position, this section out of service, and when matching board position got back to by empty backing plate, slab installs on backing plate by control device.Backing plate and slab are delivered on the dress grillage of loader (Fig. 8-10) by chain-linked conveyer (Fig. 8-9).Backing plate and slab are put on the pressing plate of hot press (Fig. 8-11) by loader, unloader (Fig. 8-12) after hot pressing, the large plate pressed and backing plate are delivered to board separating device (Fig. 8-14) through chain conveyor (Fig. 8-13), backing plate is separated with large plate, large plate transports to sander (Fig. 8-16), as product warehousing after sanding by large plate transporter (Fig. 8-15).The backing plate that board separating device (Fig. 8-14) separates to be transported to after backing plate heat sink (Fig. 8-19) cooling by chain conveyor (Fig. 8-20) through chain conveyor (Fig. 8-17,18), is transported to and joins backing plate section (Fig. 8-8) and recycle.

Carrying without backing plate is be placed directly on heating platen by slab, and carry out hot pressing by loading cart by the interval of Multi-layer thermal pressing plate feeding hot press, the plank pressed is sent by hot pressing rear shovel head.

(4) recovery and reuse technology of husk green building material: adopt a small amount of steel concrete or cement to lay bricks to make imperial frame and green building material modularization section bar is assembled into room, be easy to separately when dismantling, separately, the green building material accounting for total building materials 90% is separated, fritter is broken into crushing engine, again hot pressing or extrusion molding, makes new green building Prefabricated block section bar.

Four, the use of husk green building material and advantage:

Husk green building material is that the green building material meeting the proposition of international material Science Research Association completely requires.Base material be plant refuse, manufacturing process does not produce pollution, does not use poisonous, harmful sizing material, and reaching after life cycle can all recycling, does not produce and uses rear solid waste.In building construction, this green building material at least can be used in two, and one is, builds the non-bearing interior wall of city high-rise building; Two is the green agriculture rooms of villages and small towns standardization.Market is very vast.Have the following advantages with the house that this green building material is built: (1) house intensity is good, and design structure is elegant in appearance, and the scientific and reasonable life-span is long; (2) be wooden structures substantially, exempt from finishing, material non-toxic, harmless, "dead" material and Form aldehyde release, indoor pollution is light; Because building materials do not absorb water substantially, therefore without going mouldy, rotten sorrow.(3) sound insulation, heat insulation, fire-retardant, comfortableness is good, and safety is high; (4), install simple, construction is easy, without the need to large-scale construction equipment and specialized team; (5) to take floor space little for body of wall, house show sample and function division flexible; (6) simplify finishing, reduce the cost that builds a house, price is lower, be easy to promote.

Five, accompanying drawing illustrates: accompanying drawing 1-7 is the A-A sectional drawing producing green building material modular connecting elements section bar by Reaction extrusion method.Fig. 1 is double-deck edge sealing, and Fig. 2 is individual layer edge sealing, and Fig. 3 is flat connecting piece profile, and Fig. 4 is door sleeve, and Fig. 5 is 90 ° of corner pieces, and Fig. 6 is splicing bar, and Fig. 7 is I bar.Fig. 8 is large plate production procedure and backing plate circulation conveying schematic diagram.Fig. 8-1 in manual, to Fig. 8-20, Fig. 8 is designated as 1-20:1, spreading machine; 2, foraminous conveyer; 3, precompressed preheating machine; 4, the synchronous section of transport; 5, flying cut-off saw; 6, transport section is accelerated; 7, constant speed transport section; 8, backing plate section is joined; 9,13,17,18,20, chain conveyor; 10, slab mill is filled; 1], hot press; 12, unloader; 14, board separating device; 15, large plate transporter; 16, sander; 19, backing plate heat sink.

Six, detailed description of the invention:

Embodiment 1, manufacture green building material with husk and build the implementation step of high-story house interior wall.

First high-story house should build up framework with steel concrete by national standard, then press: (1) prepares burden to husk, stand-by energy modification its pretreatment is become to produce the material of polymer composite material, (2) with abrasive particle machine, a part of stand-by material is made stand-by pellet, (3) with the extruder transformed by modification requirement, stand-by pellet is made modular connecting elements section bar, (4) stand-by for another part material through mating formation, precompressed preheating, the large plate of husk is pressed into hot press, (5) scheme of separate room on demand in the high-story house framework built up is formulated, (6) by scheme, the interior wall in each room is assembled with prefabricated large plate and modularization connection profile, (7) decoration is carried out to the interior wall assembled.

Case study on implementation 2, with husk manufacture green building material modularization section bar build low-rise building (comprising green agriculture room) implementation step.

One-storey house or low-rise building, clearing up and building on the basis of ground, available cement is laid bricks or steel concrete, first makes (Beam, post) imperial frame.Connect at the top of imperial frame and take part in Beam, large plate that Beam mats formation, as the deck on roof.Large plate is mated formation improved plant fibrillation (its manufacture method is shown in patent 201210080798.6) as insulation, fire-retardant, separation layer.Repave last layer book plate and make pressing plate, waterproof roll that pressing plate is mated formation, as waterproofing course.Finally spread the roof tiles manufactured with improved plant fibrillation.After roof is carried out, then by step (1)-(7) of case study on implementation 1 and floor of mating formation, complete the construction in green agriculture room.

Accompanying drawing 1-8.

Claims (9)

1. The present invention is the technology of patent 201210080798.6 pairs of vegetable materials being carried out dry method modification, be applied to this specified raw material of husk, manufactured green building material Prefabricated block section bar and large plate, and be assembled into an embodiment of highrise building interior wall or low-rise building, also available other vegetable material manufacture and reference when using green building material.

   1. one kind manufactures green building material prefabricated modular section bar with husk, and be assembled into the method for highrise building interior wall and low-rise building, it is characterized in that: husk and certain batching are mixed into modification can become the material of polymer composite material by formula rate, with abrasive particle machine, a part for material is made pellet, carry out reaction modifying with the extruder transformed by modification requirement and mould to extrude, make pellet be shaped to multiple module connecting piece profile; With the heating press system transformed by modification requirement, another part material is pressed into large plate; By progresses and methods provided by the invention, husk green building material modular connecting elements section bar and large plate are assembled into interior wall and the low-rise building of highrise building again.
2. 2. according to claim 1ly can modification become the material formula of polymer composite material to be: husk, calcium carbonate, MDI (diphenylmethane diisocyanate fat), the sewage extract being dissolved with natural polymer, pvc (Corvic), THPC (or dihydroxymethyl phosphonium hydroxide).Preferably ratio is: 40%: 30%: 5%: 13%: 10%: 2%.
3. 3. the Design and manufacture of modular connecting elements section bar mold according to claim 1: comprise double-deck edge sealing, individual layer edge sealing, lateral direct type material, door sleeve, 90 degree of corner pieces, splicing bar, I bars.
4. 4. progresses and methods husk green building material connecting piece profile and large plate being assembled into highrise building interior wall according to claim 1: be installed as example with doubling plate, first double-deck edge sealing is fixed on ground or metope, by in two pieces of parallel insertion edge sealed slots of the large plate of bilayer, in two grooves of the other end parallel insertion lateral direct type material of large plate, another two blocks of large plates are inserted until corner in two grooves of the other end of lateral direct type material, on the corner two blocks of large plates are inserted in 90 degree of corner pieces, two grooves, another two blocks of large plates are inserted vertical with last side's wall in the vertical channel of corner pieces, there is piece groove the centre of lateral direct type material, will by splicing bar insertion groove, I bar is positioned in the middle of two blocks of large plates, reinforcing wall, two blocks of hollow large plates form three hollow spaces when splicing and play sound insulation, heat insulation effect, middle space can fill the functional modification plant fibrillation having done flame treatment, door sleeve is used for doing doorframe, use installation and the main distinction of the large plate of bilayer of the large plate of individual layer are relevant connectors is single groove structure, in each groove, only pacify one block of large plate.
5. 5. the method for building low-rise building according to claim 1 and program: by the design standard requirement of country, lay bricks with reinforced concrete or cement and make column dragon frame, the design and installation of body of wall are identical with claim 4, the design on roof connects to take part in Beam on the imperial frame of wall connecting, on to mat formation large plate, as deck, filling functions improved plant fibrillation in large plate, form insulation layer, isolation layer, flame-retardant layer, separation layer, pressing plate is made with one deck book plate, at pressing plate upper berth double-sided self-adhesive waterproof coiled materials, as waterproofing course, repaving with improved plant fibrillation is that the tile fragment shape precast plate that base material is made is protected and decorative layer.
6. 6. reaction modifying according to claim 1 is extruded, and pellet is made method and the program of multiple module connecting piece profile, comprise material loading, heating, plasticizing, shaping, cooling, traction, cutting.
7. 7. according to claim 1 can be polymerized, the material of recombination reaction makes method and the program of large plate, comprise slab of mating formation, with hot air, hot pressing upper plate be heated to 75 DEG C, lower plate 80 DEG C; With preformer to slab precompressed, preload pressure 1.8-2.0mpa, squeeze time 30-60 second; Flat multi-daylight press is selected after preheating precompressed, by contact-high frequency combined heat method, the temperature of 140 DEG C-160 DEG C, under 3.5-5.5mpa pressure, slab is made required sheet material, hot pressing is discontinuous, one-period comprises dress plate, closed, boosting, pressurize, step-down, unloads plate link, boosting and step-down all divide three sections to carry out, in case the generation of the problem such as bulge, layering, soft, warpage, press will have simultaneous opening and closing device, and thickness of compressive plate must meet the needs of house desigh, adopts deep fat to be the thermal medium conducting heat energy.
8. 8. the slab in large board manufacturing process according to claim 7 and the conveying of backing plate: have backing plate and without backing plate two kinds of modes, have backing plate mode of movement to divide to mat formation sawed-off, accelerate conveying, constant speed conveying, dispensing slab and backing plate circulation carry four sections of operations; Without backing plate conveying, be placed directly on heating platen by slab, carry out hot pressing by loading cart by the interval of Multi-layer thermal pressing plate feeding hot press, the plank pressed is sent by hot pressing rear shovel head.
9. 9. the recovery and reuse technology of husk green building material: adopt a small amount of steel concrete and green building material modularization section bar to be assembled into interior wall or house, green building material and concrete solid waste to be separated when dismantling, separately, green building material is separated, fritter is broken into crushing engine, again by claim 6,7,8, method and program, again hot pressing or extrusion molding, makes new green building Prefabricated block section bar, then is assembled into interior wall and low-rise building by claim 4,5.