2314 results about "Precast concrete" patented technology

Disclosed are apparatus and corresponding methodology for providing a base support, such as including concrete, and used such as for a wind-driven generator. Precast concrete cylinders are stacked in place upon a platform that may be partially precast and partially cast in place during assembly and supported, in certain embodiments, by plural concrete legs, the other ends of which are supported on a unitary or subdivided concrete foundation. In other embodiments, the platform may be supported by ribbed concrete panels. The concrete cylinders are glued together using an epoxy and then secured by an internal vertical post tension system extending from the platform to the upper most cylinder. Different types of concrete are used between upper and lower sections of the stacked cylinders. The lower section uses reinforced concrete while the upper section used ultra high performance fiber reinforced concrete.

The invention relates to a node connection device for a self-centering prestressed concrete frame. The node connection device is a device used for the connection between the beam and the column of a prefabricated reinforced concrete frame, and aims at improving energy consumption of a frame structure under seismic action and eliminating or reducing the residual deformation and damage of the frame structure. The connection device is characterized in that combined steel parts form an energy consuming device, two external friction steel plates (3) are arranged in the energy consuming device, are respectively and symmetrically arranged on the two sides of a column end reinforcing steel plate (4) and are connected with the column end reinforcing steel plate (4) into a whole body, two internal friction steel plates (8) are arranged between the two external friction steel plates (3), the upper end and the lower end of each internal friction steel plate (8) are respectively provided with a bean end reinforcing steel plate (5), friction discs (15) are respectively arranged between the two internal friction steel plates (8) and the two external friction steel plates (3), and friction-type high-strength bolts (12) penetrate through the external friction steel plates (3), the friction discs (15), the internal friction steel plates (8) and a prefabricated concrete beam (2) and connect all parts together.

The invention relates to an assembled monolithic shear wall building structure and a construction method thereof, and belongs to the technical field of buildings and construction thereof. The assembled monolithic shear wall building structure is formed by connecting prefabricated concrete members which comprise a prefabricated wall plate member, a floor member, a T-shaped wall column member, an L-shaped wall column member, a cross wall column member and a wall member with an opening. The structure is characterized in that a plurality of longitudinal through holes which are parallel to the surface are formed in each prefabricated concrete member; transverse grooves crossed with at least one longitudinal hole are formed on the longitudinal edge at intervals; transverse anchoring steel bars are arranged at the transverse grooves among different prefabricated members; longitudinal anchoring steel bars are arranged in the longitudinal holes; a layer of structural unit or a single-layer building structure is formed by filling concrete in the longitudinal holes and the transverse grooves; and a plurality of structural units are connected to form a multi-layer or high-rise assembled monolithic shear wall structure. The structure can be used in a multi-layer or high-rise shear wall building structure and a frame-shear wall building structure, the industrial level of the building structure can be improved, stress performance is improved, and resources are saved.

Embodiments of the invention provide a slag manufactured aggregate suitable for inclusion in one or more of concrete, precast concrete, cellular concrete, or precast cellular concrete. Concretes, precast concretes, cellular concretes, and precast cellular concretes comprising the slag manufactured aggregate are also included in embodiments of the invention. Methods of making the foregoing aggregates and concretes are also included herein.

The invention comprises a product. The product comprises a foam insulating panel, the panel having a first primary surface and an opposite second primary surface, wherein the foam insulating panel defines at least one recessed channel in the first primary surface, the at least one recessed channel being sized and shaped to provide a mold for a structural reinforcing member. The product also comprises a concrete panel formed on the first primary surface and filling the at least one recessed channel so as to provide a structural reinforcing member for the concrete panel. The product further comprises an elongate anchor member in the foam insulating panel and extending from the first primary surface of the foam insulating panel into the concrete panel. A method of making a composite reinforced insulated concrete structure is also disclosed.

A process for making a pervious concrete comprising a geopolymerized pozzolanic ash. Generally, the process includes mixing a solid aggregate and a geopolymerized pozzolanic ash binder together to form a pervious concrete mixture. Some examples of suitable aggregates comprise recycled carpet, recycled cement, and aggregates of coal-combustion byproducts. The geopolymerized pozzolanic ash binder is made by combining a pozzolanic ash, such as fly ash, with a sufficient amount of an alkaline activator and water to initiate a geopolymerization reaction. The activator solution may contain an alkali metal hydroxide, carbonate, silicate, aluminate, or mixtures thereof. In some aspects, the final concrete forms a solid mass in the form of pavement or a pre-cast concrete shape. The solid mass of concrete may have a void content of between about 5% and about 35%.

A pre-fabricated concrete slab system and method have matching rectangular male and female type slabs which fit adjacent to each other in a checkerboard fashion. The male slabs include spaced reinforcing rods extending longitudinally and transversely through the male slabs with the rods' distal ends protruding outwardly away from one or more side edges of the male slabs to form a plurality of male connectors. The female slabs include a plurality of corresponding female sockets on one or more sides of the female slab, each female socket receiving a corresponding male connector when dropped therein. Corresponding female sockets positioned on opposite side edges of the female slabs are interconnected by steel reinforcing bars in both the longitudinal and transverse directions in a configuration similar to the male slabs so that, when connected, a continuous tension reinforcement is established between male and female slabs in both the longitudinal and transverse directions.

The invention discloses a fractured rock mass stress and seepage coupled testing system and a fractured rock mass stress and seepage coupled testing method, belonging to testing systems and methods for fractured rock mass or pore medium seepage of rock and soil and geology. The system is divided into three parts, namely a seepage experiment device, a stress and displacement loading system and a data acquisition system, wherein the seepage experiment device can load square fractured rock mass or precast concrete crack samples, and a water pump provides power to form a test loop seepage channel; a control valve, an energy accumulator, a filtering device and a pressure and flow sensor are arranged on a water inlet/outlet pipe connected with the seepage experiment device; the stress and displacement loading system is equipped with a hydraulic cylinder driven by an oil pump and a trapezoidal screw; the hydraulic cylinder and the trapezoidal screw are matched with the pressure and flow sensor, so that the pressure and displacement can be accurately regulated and controlled; an unrelated three-degree-of-freedom sliding system is formed by a flange bearing, a cylindrical pin and a small ball, so that loading is not interfered by friction and other adverse factors; and moreover, all data in the experimental process is acquired and recorded by the data acquisition system in real time.

The invention relates to a tunnel lining self waterproof drainage system, which comprises a surrounding rock bearing arch, a cast-in-place cement main waterproof layer, a pre-cast cement arch sheet layer and longitudinal drainage channels. Arch sheet layer construction gaps and cast-in-place cement main waterproof layer construction gaps are interlaced. The tunnel lining self waterproof drainage system is characterized in that movable drainage grooves are fixedly arranged below the pre-cast cement arch sheet layer of centralized bursting water seepage points of loose surrounding rocks, and form arch sheet drainage spaces with an inwards concave surface of the pre-cast cement arch sheet layer, the parallel drainage spaces distributed along the section of a tunnel form a movable drainage channel, the longitudinal drainage channels are communicated and are arranged on two sides of the movable drainage channel and the pavement of the tunnel, pre-embedded water guiding pipes are arranged at the centralized bursting water seepage points, a water outlet end of each pre-embedded water guiding pipe is arranged on the inwards concave surface of the pre-cast cement arch sheet layer, and pre-embedded grouting pipes are arranged outside the pre-embedded water guiding pipes. The invention completely solves stubborn problems of the tunnel on cracking, seeping, frost heaving, ponding or freezing and the like on the premise of not arranging an interlayer waterproof layer and a hidden seepage water blind pipe drainage system, and the tunnel lining self waterproof drainage system disclosed by the invention has a simple structure and is convenient to construct.

The invention comprises a method of forming a concrete structure. The method comprises placing plastic concrete in a form of a desired shape, encasing the concrete in insulating material having insulating properties equivalent to at least 1 inch of expanded polystyrene and allowing the plastic concrete to at least partially cure inside the insulating material. An insulated concrete form and a method of using the insulated concrete form are also disclosed.

A post-tensioned precast segmental concrete tower has a stack of annular segments with uniform cross-sections which varies over the tower height. The transition between tower segments occurs in stages and is achieved using annular members or segments which support and anchor post-tensioning tendons that transfer loads passing through the tower as a result of a change in tower geometry. The tower segments are match cast against one another in fabrication to create tight matching opposing surfaces when placed into the tower and to create tight joints. The match casting eliminates the need for grout between precast segments, resulting in a faster tower erection time and high durability of the joints. All annular segments have horizontal joints and no vertical joints. The tower geometry simplifies the formwork system used to precast the segments, and the post-tensioning tendons tie all segments together and to the foundation.

A retaining element system is provided that improves face stability in poorer quality soils that are not suited to conventional soil nailing. The method includes inserting retaining elements substantially vertically into an earthen mass to shore the face of an excavation. The earthen mass can be any material or combination of materials, such as soil, clay or rock that requires excavation for the installation of a shoring wall. The plurality of retaining elements are placed side by side in a substantially linear arrangement. A plurality of soil nails are then inserted into the excavation plane, at the approximate midpoint between a pair of adjacent retaining elements. An exposed tip portion of each soil nail attaches to a wale, which is a substantially horizontal element that contacts a retaining element on both sides of each soil nail. The wale can be a beam, bracket, or a set of concrete reinforcement bars. The beam or bracket can either be a structural member, formed of steel or the like, or alternatively formed from a precast concrete. The concrete reinforcement bars can then receive a concrete fill to form a solid wale structure. Face stability is achieved with the pre-installed retaining elements, which with the wales provide complete facing support.

The invention discloses a steel-concrete composite beam adopting a corrugated steel web, which relates to a corrugated steel web composite beam capable of being applicable to highway bridges and railway bridges. The beam comprises a top flange concrete composite plate, a corrugated steel web plate, a top flange steel plate, a box beam bottom plate and male pin connecting pieces, wherein the top flange comprises a precast concrete slab and a cast-in-place concrete layer; and the top flange concrete composite plate is connected with the top flange steel plate into a whole through the male pin connecting pieces welded on the top flange steel plate. By adopting the structure, the problems that the site workload and the construction difficulty for casting a bottom flange concrete slab of a traditional corrugated steel web composite beam are large, the construction quality is difficult to guarantee and the like are overcome on the premise that the quantity of steel is hardly increased, meanwhile, the tensile property of the steel plate is fully played, the bearing capacity, the rigidity and the cracking resistance of the structure are improved, and the durability of the structure is improved, therefore, the corrugated steel web composite beam has the advantages of simple structure, reasonable stress, quick and convenient construction, and good technical and economic benefits.

The invention provides a nano suspension liquid concrete early strength agent and a preparation method thereof. The nano suspension liquid concrete early strength agent is prepared from transition metal element doped nano calcium metasilicate suspension liquid, the suspension liquid is mainly composed of nanometer silicon particles, the chemical structure of the nanometer silicon particles is aCaO.bAl2O3.cZnO.SiO2.6H2O, 1<=a<=2, 0.50<=b<=1, and 0.25<=c<=0.50. The nanometer silicon particles are prepared from soluble calcium salt, soluble silicate, soluble aluminum salt, soluble zinc salt and a high polymer dispersing agent. On the one hand, the early strength agent contains no chlorine salt and has no corroding function on steel bars in concrete; on the other hand, an extremely stable suspension liquid system is achieved, adding is facilitated, and the early strength agent can be evenly dispersed easily in the concrete preparation process. The early strength of concrete can be remarkably improved, the early strength effect on concrete adopting highly-doped mineral admixtures is especially obvious, the early strength agent is especially suitable for production of precast concrete components, and a steam maintenance process can be effectively reduced and even omitted.

The invention relates to the technical field of fabricated concrete frame structures, and discloses a pre-stressing-force fabricated concrete-frame-joint connecting structure and a construction method thereof. The pre-stressing-force fabricated concrete-frame-joint connecting structure comprises a prefabricated concrete column, a prefabricated concrete superposed beam, a composite floor slab, a post-tensioned pre-stressing tendon, an anti-bending and energy-consuming reinforcing steel bar and a shear-resistant and high-strength reinforcing steel bar, wherein the post-tensioned pre-stressing tendon, the anti-bending and energy-consuming reinforcing steel bar and the shear-resistant and high-strength reinforcing steel bar are connected with the prefabricated concrete column and the prefabricated concrete superposed beam. A beam post-pour layer of the prefabricated concrete superposed beam and a slab post-pour layer of the composite floor slab are poured integrally, the inner portion of a beam column seam between the prefabricated concrete superposed beam and the prefabricated concrete column is filled with high-strength crack-pouring binding materials, the anti-bending and energy-consuming reinforcing steel bar and the shear-resistant and high-strength reinforcing steel bar are laid in the beam post-pour layer of the upper portion of the prefabricated concrete superposed beam, and the anti-bending and energy-consuming reinforcing steel bar is located above the shear-resistant and high-strength reinforcing steel bar. According to the pre-stressing-force fabricated concrete-frame-joint connecting structure and the construction method thereof, efficient construction can be achieved, the anti-seismic property and the progressive-collapse-resistant capability are good, and post-earthquake repairing is facilitated.

A lifting apparatus to be embedded within a precast concrete panel or slab to enable the panel to be lifted, positioned atop a road bed, and elevated above the road bed. A lifting apparatus is located at each corner of the panel. Each lifting apparatus has a threaded sleeve extending through the panel to receive a removable threaded lifting bolt by which to establish a lifting point at which a lifting force is applied to lift and position the panel. When the threaded lifting bolt is rotated completely through the threaded sleeve, a pushing force is applied against a base plate, whereby to elevate the panel above the road bed as is necessary to make the panel level with adjacent panels during the construction or repair of a roadway. Grout is pumped through the panel to fill the space between the panel and the road bed.

The invention relates to a friction energy consumption type node connection device for a self-centering pier column structure, which is a device used for connecting a bridge pier or a frame column with a pile cap (a foundation), so as to improve the energy consumption of the pier column structure under the action of earthquake and eliminate or reduce the residual deformation and the injuries of the structure. The device comprises a pier column strengthening steel plate, a foundation pre-embedded steel plate, an angle steel, a friction bolt, a friction plate, unbonded prestressed tendons, an anchor bolt and the like. The device can connect a concrete pier column and the foundation into a whole through the unbonded prestressed tendons which are vertically arranged. When the earthquake strength achieves a certain degree, the pier column-foundation contact surface is open, and the pier column can produce a certain rotation relative to the foundation. A friction device can dissipate earthquake energy through friction at this time, and the prestress provided by the prestressed tendons can recover the structure to the initial position after the earthquake. A pre-embedded part at the end part of the pier column is used for improving the local bearing pressure of the concrete when the pier column rotates relatively.

A lifting and leveling assembly configured to be embedded in a precast concrete slab for lifting a leveling a precast concrete slab includes a base plate, a threaded sleeve, an anchor plate, a thread protecting sleeve, a threaded lifting bolt and an end cap. Rotating the threaded lifting bolt in a first direction positions a bolt head on the threaded lifting bolt above a top surface of a precast concrete slab to accommodate the attachment of a lifting device. Rotating the threaded lifting bolt in a second direction positions the bolt head beneath the top surface of the concrete slab and causes the threaded shaft to exert a force on the base plate to level the precast concrete slab.

The invention discloses a reinforced concrete structure based on 3D printing and a structure construction method. The method comprises the following steps that a foundation bottom plate is constructed, and a connection section is reserved on the foundation bottom plate; a steel bar structure of a structural column is bound to the connection section; a first prefabricated concrete outer shell is manufactured by adopting 3D printing, and concave-convex lines are formed in the inner surface of the first prefabricated concrete outer shell; the first prefabricated concrete outer shell is arranged on the steel bar structure of the structural column in a sleeved mode; a steel bar structure of a structural beam is bound, and the steel bar structure of the structural beam is bound to the steel bar structure of the structural column; a second prefabricated concrete outer shell is manufactured by adopting 3D printing; the second prefabricated concrete outer shell is mounted on the steel bar structure of the structural beam; concrete is poured in the second prefabricated concrete outer shell, and the structural beam and the structural column are completed. The prefabricated concrete outer shells are formed integrally by adopting a 3D printing technology, the continuous concave-convex lines are formed in the inner surfaces of the prefabricated concrete outer shells, the contact surfaces between the concrete poured in the prefabricated concrete outer shells and the inner surfaces of the prefabricated concrete outer shells are enlarged, compared with a smooth inner surface, friction is increased, bonding strength is improved, and a shell disengagement phenomenon is avoided.

The invention provides a nano-suspension concrete early strength accelerator which can be stably dispersed in an aqueous solution and is prepared from a thixotropic solution and a nano-calcium silicate suspension according to mass ratio of 1:4-9. The thixotropic solution is prepared from the following ingredients, by weight, 15-25% of soluble fluosilicate, 20-35% of soluble aluminium salt and the balance being water. The nano-calcium silicate suspension is prepared from the following ingredients, by weight, 5-20% of soluble silicate, 8-18% of soluble calcium salt, 3-10% of a high-molecular polymer dispersant and the balance being water. The invention also provides a preparation method of the early strength accelerator. On one hand, the early strength accelerator contains no chlorine salt and has no corrosion effect on steel bars in concrete. On the other hand, the early strength accelerator is a stable suspension system, is convenient to add and is easy to uniformly disperse during the preparation process of concrete; and the early strength accelerator can remarkably raise early strength of concrete, has an obvious early strength effect especially on concrete obtained by the use of high volume of mineral admixtures and is especially suitable for production of precast concrete components.

A foundation interface for a concrete foundation for the support of a structure comprises a prefabricated concrete element with a plurality of through holes, which are geometrically arranged to correspond to an arrangement of holes or bolts of a structure to be supported. Further, a method for fabricating a concrete foundation comprising such a foundation interface is provided.

A precast concrete wall panel molding system for fabricating a wall shell and a plurality of ribs and beams. A precast concrete wall panel molding system with facilities for incorporating door and window frames. A ductile panel end connector for attaching panels one to another whether in parallel or angled as in inside or outside corners. A ductile panel end connector for attaching panels to columns. A wall anchor/shear plate with post-tensioning brace plate. A hybrid precast/cast-in-place special moment resisting shear wall/special moment resisting frame reinforced concrete building system for regions of potential seismic activity. A prescriptive method building system for composite structural building assemblies with conventional wood and light-gauge steel framing, structural steel, and other building code approved and tested building systems, building components, building panel systems, building roofing systems, modular and manufactured buildings, and building electrical, mechanical, and plumbing systems. A precast concrete wall panel system conforming to industry practices and standards as published by the Precast/Prestressed Concrete Institute, (PCI) in it's “PCI Design Handbook” (fifth edition, 1999), the American Concrete Institute “Building Code Requirements for Structural Concrete” (ACI 318-05), The “International Building Code 2006” and the “Uniform Building Code”.

The invention discloses a streamlined steel-concrete superimposed box girder, which relates to the technical field of bridge engineering and is used for a long-span bridge girder. Two sides of the superimposed box girder are provided with tuyere structures, and a bridge panel adopts a superimposed structure consisting of prefabricated concrete slabs and a post-poured concrete layer. When the box girder is in use, the superimposed box girder is a streamlined single-box single-chamber or single-box multi-chamber cross section; the tuyere structures are polygonal open thin-walled structures; and longitudinal-transverse prestress is applied in the superimposed bridge panel. The box girder effectively improves the torsional rigidity and wind-resistant stability of the section of the girder, remarkably improves the integrity and durability of the bridge panel, and expands the application of superimposed girders in cable-stayed bridges and other long-span bridges.

The invention relates to a corrugated steel webplate combined box girder floor system for a cable-stayed bridge and a construction method thereof, and belongs to the technical field of bridge structures. The corrugated steel webplate combined box girder floor system comprises a precast concrete plank and a cast-in-place concrete seam, wherein the precast concrete plank is positioned on a steel box girder and is integrated with the steel box girder into a whole; the steel box girder is formed by welding a top flange steel plate, a corrugated steel webplate and a steel plate at the bottom of the box girder; a box girder baseplate stiffening rib and a diaphragm plate are welded in the steel box girder; the diaphragm plate comprises a top flange steel plate of the diaphragm plate and a steel webplate of the diaphragm plate; a toggle pin connecting piece is welded on the top flange steel plate and the top flange steel plate of the diaphragm plate; and a steel anchor pulling plate and a steel sleeve are welded on the top flange steel plate. The corrugated steel webplate combined box girder floor system simplifies the manufacturing process for the precast concrete plank, gives full play to the superior mechanical property of the corrugated steel webplate and the release action of the corrugated steel webplate on the creep effect of concrete shrinkage, improves the bearing capacity, stiffness and crack resistance of the structure, and improves the durability of the structure.

The invention discloses a pre-fabricated concrete box culvert, the assembly structure thereof and an assembly method. The invention can ensure that the mortar is completely filled on a connecting surface of the pre-fabricated concrete box culvert, thereby furthest reducing the pre-stress damage caused by the sliding when the reinforcing steel bar is fixed, and allowing the pre-fabricated concrete box culvert to be assembled into a structure with extremely strong adhesion force, firmness and reliability, furthest reducing the loss of the bundled reinforcing steel bars and avoiding the damage to the structure.

The invention relates to a prefabricated assembled superposed plate type concrete shear wall and a construction method thereof. The prefabricated assembled superposed plate type concrete shear wall comprises superposed wall plates and a cast-in-place concrete core wall, wherein each superposed wall plate is formed by superposing two prefabricated concrete single wall plates which are of the same specification and are symmetrically arranged at an equal interval; supporting plate steel bar supports are arranged between the two single wall plates; node connection reinforcement steel bars are arranged on end nodes of the superposed wall plates; the superposed wall plates are fixedly integrated with the cast-in-place concrete core wall; and the superposed wall plates, the cast-in-place concrete core wall, the supporting plate steel bars and the node connection reinforcement steel bars are fixedly connected with one another to form the shear wall structure. The invention also provides a construction method for the shear wall structure. By the construction method, when an extensive form building mode is changed, and structural members of a house are standardized and modularized, engineering construction is high in speed, and materials are saved; and the overall structural performance is high.

The invention relates to an assembly integral shear wall building structure and a building method and belongs to the field of buildings and construction technologies of the buildings. The shear wall building structure is formed by connecting prefabricated concrete hollow components through steel bars and cast-in-place concrete, wherein the prefabricated concrete hollow components include prefabricated wall body components, floor board components, T-shaped wall pillar components, L-shaped wall pillar components, cross-shaped wall pillar components and wall body components with holes. Multiple parallel lengthwise through holes are formed in the prefabricated hollow components in the length direction and multiple parallel transverse non-through holes communicated with the lengthwise through holes are formed in the prefabricated hollow components in the width direction. Horizontal anchor connection steel bars inserted into the transverse holes are arranged among the different prefabricated components. Lengthwise anchor connection steel bars are arranged in the lengthwise holes, wherein one end of each lengthwise anchor connection steel bar protrudes out of the surface of the corresponding prefabricated component by a certain length. The concrete is filled into the lengthwise holes and the transverse holes to form a layer of structural unit or a single-layer building structure. Multiple structure units are connected to form a multiple-layer or high-rise assembly integrated shear wall structure. The assembly integral shear wall building structure and the building method can be applied to the multiple-layer or high-rise shear wall building structures and frame-shear wall building structures. Thus, the industrial level of the building structures can be improved, stress performance can be improved and resources are saved.

The invention discloses a novel assembling type precast concrete urban comprehensive pipe gallery and a construction method thereof. The novel assembling type precast concrete urban comprehensive pipe gallery comprises a plurality of inverted u-shaped cover plates and a plurality of substrate plates, wherein each inverted u-shaped cover plate comprises a cross plate, a left vertical plate and a right vertical plate; each substrate plate comprises a bottom plate, a left convex plate and a right convex plate; the middle position of each left convex plate and each right convex plate is provided with troughs; each left vertical plate and each right vertical plate are respectively installed in each left convex plate and each right convex plate; the middle position of each bottom plate is provided with a central drain. The construction method of the novel assembling type precast concrete urban comprehensive pipe gallery comprises the following steps: preparing prefabticated members; excavating and timbering a foundation pit; laying a cushion ply; connecting the inverted u-shaped cover plates with the substrate plates; connecting the inverted u-shaped cover plates, and connecting the substrate plates; tensioning, smearing gaps, backfilling and carrying out form stripping. The novel assembling type precast concrete urban comprehensive pipe gallery has the advantages of convenience in transportation, construction and maintenance, simpleness in operation and high construction efficiency, and the structural integrity and stability of a gallery body can be improved, and the water resistance and water discharging performances of the pipe gallery can be improved.

The invention relates to a coal mining method for a high-dipping low coal seam by long-wall mining. The method comprises the following steps of: supporting a roof by a self-advancing air bag support; arranging a working surface in a mode of advancing to the dip; mining coal by drilling and blasting or using an off-pan shearer; transporting the coal in a mode of gravity haulage; filling a goaf with gangue or sand; and filling a lower end with gangue bags, precast concrete blocks or solidified macromolecular foaming slurry. The coal mining method has the advantages of realizing mechanical coal mining for the high-dipping low coal seam, improving the yield per unit and efficiency of the working surface, effectively protecting the exploited ground, improving the recovery rate of mines, and guaranteeing the coal seam mining safety.

Adjacent precast reinforced concrete modules or members are secured together by a plurality of coupler systems each including a cast metal coupler body embedded in an edge portion of the first concrete member and connected by a coupling member to a reinforcing bar within the first concrete member. The coupler body has an internal cavity with a side opening and an end opening extending to the cavity, and reinforcing wings border the side opening. The second concrete member has another coupling member rigidly connected to an axially aligned reinforcing bar and includes an end portion with a threaded bore. A bolt is inserted into the cavity through the side opening, aligned with the end opening and then threaded into the bore where the bolt is tightened with a wrench extending into the cavity through the side opening. A reusable locating pin may be used to align the concrete members.