Jointless Composite Concrete Slabs Shrinkage Control
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Solution Overview
Problem
Existing composite concrete compositions for industrial floors and rafts suffer from limitations such as long-term cracking, curling edges, joint opening, and high cement consumption, restricting slab size and durability.
Innovation Solution
Incorporating a shrinkage-reducing additive like free lime, ethylene glycol, or calcium sulfoaluminate into the composite concrete, along with steel and synthetic fibers, to create a composition that allows for thin, fully jointless slabs with enhanced energy absorption and zero shrinkage, using specific cement types and fiber ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If steel fibers are used to control cracking, then cracking resistance is improved, but shrinkage and joint opening are not eliminated
Solution Approach 1:
The patent combines steel fibers with shrinkage-reducing additives (such as calcium sulfoaluminate, free lime, or ethylene glycol) to create a composite concrete formulation that simultaneously achieves cracking resistance and shrinkage control. This composite approach allows the concrete to benefit from both the tensile reinforcement of steel fibers and the shrinkage-compensating properties of the additives, eliminating joint opening while maintaining crack control.
Solution Approach 2:
The patent modifies the chemical composition parameters of the concrete by incorporating specific shrinkage-reducing additives in controlled amounts (e.g., calcium sulfoaluminate at 0.5-2% of cement mass). This parameter change fundamentally alters the concrete's shrinkage behavior, transforming it from a material that opens joints to one that maintains joint closure while still providing cracking resistance through steel fiber reinforcement.
2Object-generated harmful factors
If slab thickness is reduced to eliminate curling, then edge curling is reduced, but slab strength and durability are compromised
Solution Approach 1:
The patent uses a composite formulation combining steel fibers with shrinkage-reducing additives to achieve sufficient strength and durability in thinner slabs. The steel fibers provide tensile reinforcement and crack control, while the shrinkage-reducing additives prevent joint opening and edge curling. This composite approach allows thin slabs (5-15 cm) to maintain adequate strength and durability without the curling problems that plague thinner conventional concrete slabs.
Solution Approach 2:
The patent applies local quality enhancement by concentrating steel fiber reinforcement and shrinkage-reducing additives in the concrete mixture, creating localized zones of enhanced strength and shrinkage control within the thin slab structure. This allows the thin slab to maintain sufficient structural performance despite reduced overall thickness.
3Reliability
If joints are introduced to control shrinkage, then shrinkage movement is concentrated in joints, but joint opening and slab complexity increase
Solution Approach 1:
The patent extracts the shrinkage control function from the mechanical joint structure and transfers it to the concrete material itself through the addition of shrinkage-reducing additives. This eliminates the need for joints to control shrinkage, allowing for fully jointless slabs while maintaining effective shrinkage control through the chemical composition of the concrete.
Solution Approach 2:
The shrinkage-reducing additives enable the concrete to control its own shrinkage internally, without requiring external joint structures. The concrete essentially serves itself by containing the shrinkage-reducing agents within the mixture, allowing it to self-regulate dimensional changes and prevent joint opening without needing divided slab sections.
4Area of stationary object
If slab area is increased to reduce joints, then jointless coverage is improved, but cracking and curling increase
Solution Approach 1:
The patent employs a composite concrete formulation with steel fibers and shrinkage-reducing additives that enables large-area jointless slabs to resist both cracking and curling simultaneously. The steel fibers provide distributed tensile reinforcement across the entire slab area, while the shrinkage-reducing additives prevent the shrinkage-induced stresses that would otherwise cause cracking and curling in large jointless areas.
Solution Approach 2:
The patent changes the fundamental material parameters of the concrete by incorporating shrinkage-reducing additives, which fundamentally alter the stress-strain behavior of the concrete in large slabs. This parameter change allows large-area jointless slabs to maintain dimensional stability and resist cracking and curling throughout the entire extended area without the need for joints.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables the construction of thin, fully jointless composite concrete slabs and rafts with unlimited area coverage, zero shrinkage, and high energy absorption, surpassing previous limitations in size and durability.
Implementation Method 1
it additionally contains at least one shrinkage reducing additive chosen from a group comprising free lime, ethylene glycol and calcium sulfoaluminate
Implementation Method 2
The reinforcing of concrete floors may also be obtained by randomly mixing fibers into the concrete. The fibers may consist of steel wire or steel cuttings, or of synthetic fibers
Implementation Method 3
The composition contains cement, water, sand-stone mixture with particle size to 16 mm, fibers and plasticizer
Data Source
AI summary
The invention is in the field of construction and can be used for constructing industrial floors and foundation slabs. The offered composite concrete mixture, comprising cement, sand-stone mixture, water, plasticizer, nano-size pozzolans, shrinkage reducing additive, and steel and/or synthetic fibers, allows the construction of thin, completely jointless without limitation of area, large composite concrete slabs, with no observable shrinkage cracks or curling.