Concrete slab moisture can cause problems with the adhesion of floorcovering material, such as tile, sheet flooring, or carpet and bondrelated failures of nonbreathable floor coatings. Oneway simply supported slab analysis and design of the slab similar to design of simply supported beam as indicate in the previous chapter. Although many concrete slabs can satisfactorily be cast directly on a soil subgrade, some slabongrade sys tems can be significantly improved by the addition of. Some foundations used for light buildings on shrinkswell soils. The alternative to using this guide is to go to title 210 national engineering manual, section. Posttensioned concrete design table 11 list of symbols used in the aci 31808 code m bal design moment resistance of a section with tendons and the necessary mild reinforcement to reach the balanced condition, nmm m u factored moment at section, lbin n c tension force in concrete due to unfactored dead load plus live load, lb p. Guide for design of jointed concrete pavements for streets and local roads aci 325. Foundations come in many types, and each one has its strengths and weaknesses. Ce 437537, fall 2002 slab on grade example design info 1 8 design the thickness for a slab on grade concrete slab in a warehouse. Besides these advantages, there are significant cost savings to the builder and owner by using the cupolex flooring formwork in the design of aerated concrete slabs for residential, industrial, commercial. The designer determines the required slab thickness after determining the controlling loads, the appropriate safety fact o r, and the subgrade modulus.
It includes general information to consider when working with nudura in both plan and vertical section layout including. Aci 360, design of slabs on grade, refers to this as a type b slab. Batters are marked and placed in position as per plan before concrete pour. Floor slab design floors are designed as slabs on grade. Proper preparation providing an adequate subgrade for your planned slab on grade is one of the main keys to longterm performance. Concrete mix design is the procedure for finding the right quantities of these materials to achieve the desired strength. Design a thickened slab to support the columns and. Find the following parameters for design moments in step 2 per unit width step 4 note. Foundation analysis and desing foundation design 1.
Information on other aspects, su ch as materials, construction methods, placement of concrete, and finishing techniques, is. The shear area of concrete is entered as input to some computer programs when the analysis is required to take into account the deformations due to shear. Your uniform load of 100 psf will generate only minimal flexural stresses in the concrete, largely due to irregularities of the slab thickness and non uniform compaction of the soil beneath it. The wire reinforcing institute recommends the use of the subgrade drag theory for slabs up to 150 feet in length. Different grades of concrete, their strength and selection. Floor slabs can range from a simple residential basement slab to a heavyduty industrial floor. Design is defined as the decisionmaking process of planning, sizing, detailing, and developing specifications preceding construction of slabs onground. Design and construction of concrete slabs on grade, aci scm1186, american concrete institute, detroit, 1986. Guide for design and construction of concrete parking lots. How to design a concrete slab on grade duane craig pin share tweet share email a foundation is an extremely critical part of the building. Consequently, aci 360 was formed with this mission. The wire reinforcing institute recommends the use of the subgrade drag. Pdf aci 360r92 design of slabs on grade reported by aci. Tm 580912 concrete floor slabs on grade subjected to.
Other than these flexural stresses, its only when you. Most aci standards and committee reports are gathered together in the annually revised aci manual of. Concrete floor slabs employing portland cement, regardless of slump, will start to. Lecture series on design of reinforced concrete structures by prof. The contractor shall construct a reinforced concrete slab of 6. Design concrete slab on grade concrete engineering general.
Concrete floor slabs on grade are subjected to a varie ty of loads and loading conditions. Dhang, department of civil engineering, iit kharagpur. The design procedure includes determining slab thickness based. Reported by committee 302 american concrete institute. Slabs which are directly laid on the earth to support walls and other structural elements are called as slab on grade or grade slabs.
Mar, 2019 slab thickness design for industrial concrete floors on grade is195. Empirical method a method of design and analysis based on a nationally approved or equivalent standard may be used to design slabs on grade as foundations. Concrete slab rest ing on grade cont aining steel reinforcement which consists of either a welded wire fabric or deformed reinforcing steel bars. Design and investigation of concrete foundations, mats, combined footings, pile caps, slabs on grade. Stresses in concrete slabs come from volume changes in the concrete from shrinkage and temperature changes or from imposed loads. Slab on grade or grade slab types construction procedure. Design guide 11 floors slabsonground for concrete structures. Design of slabs on ground aci 360r06 by american concrete institute slab thickness design for industrial concrete floors on grade is195. Introduction concrete slabs on grade are a very common type of concrete construction. Design the minimum slab thickness to support a fork lift specified below and storage racks specified below throughout. There are two different types supported slab on grade and monolithic slab on grade. Learn more about construction procedure with video explanation. Concrete slab on grade analysis calculator for post or wheel. Stiffened slab on grade elevated structural slab on piers stiffened slab on grade and on piers thin post tensioned slab figure 1.
Stresses in floor slabs on grade resulting from vehicular loads a re a function. Aci 360r10 guide to design of slabsonground american. When a house has a concrete slabongrade with a thickened edge forming its perimeter foundation also called a turneddown slab edge, one no. Reinforced concrete design 1 design of slab examples and. Concrete slab on grade concrete building engineering. The construction and design of concrete slabs on grade d. The materials to be used are grade c25 concrete and grade. Grade of concrete construction is selected based on structural design requirements. Nominal mix concrete are those which are generally used for small scale construction and small residential buildings where concrete consumption is not high.
Type d, slab posttensioned for choosing design methods for industrial floor slabs by boyd c. Packard portland cement association, 1976 concrete floor slabs on grade subjected to heavy loads army technical manual tm 580912, air force manual afm 883, chapter 15 1987. Investigate whether the slab has adequate flexural capacity. A good tool for thickness design with various nonuniform loads is concrete floors on ground, published by portland cement association farny. The most common reinforcement associated with slabsongrade is welded wire fabric. Concrete mix design calculation m20, m25, m30 procedure. Ce 437537, fall 2002 slabongrade example design info 1 8. Slab design reading assignment chapter 9 of text and, chapter of aci31802 introduction aci318 code provides two design procedures for slab systems. I have a two storey building, and my second floor and roof loads are transmitted to column footings below my slab on grade. Now, i just need to design my slab on grade for a relatively small uniformly distributed load live load 4.
And then, soil investigation is done to design the thickness of the slab. Concrete pavement design, construction, and performance. Reinforcing steel in slabs on grade concrete construction. Concrete floor slabs on grade are subjected to a variety of loads and loading conditions. Sep 03, 2011 reinforced concrete sk 33 section through slab showing stress due to moment. Concrete slab resting on grade containing steel reinforcement which consists of either a welded wire fabric or deformed reinforcing steel bars. In general, a slab on grade strength is largely dependent on the quality of the soil beneath it. Online concrete slab on grade analysis calculator for slab subjected to interior concentrated post or wheel loading assuming slab is reinforced for shrinkage and temperature only. Powered by a sophisticated fem solver increasing capacity and substantially speeding up solution for large and complex models, spmats v8. Development of the design approach the primary design issues for stiffened slabs on grade are the sizing of the beams.
Both slab on grade and structural slabs can be created using this formwork. Pdf slab thickness design for industrial concrete floors. General design process though many details must be included in the design of a slab on grade, three important components are slab thickness, reinforcement requirements, and joint spacing. Stresses in floor slabs on grade resulting from vehicular loads are a function of. Detailed procedures are given for the design of concrete pavement for runways, taxiways, and aprons, including simplified design charts for determining slab thickness for. The major structural components of a slab on grade foundation are the floor slab itself and either grade beams or foundation walls with footings at the perimeter of the slab see figures 42 and 43. The 6 slabs on grade is unreinforced and supported on soil with a subgrade modulus of 100 kcf.
A stemwall with slab on gradesupports the wall above and often also provides a brick ledge to support an exterior masonry veneer. This video shows you how to calculate the amount of concrete required to pour a concrete slab on ground with splayed edge beam and a rebated. Aci 360, design of slabsongrade, refers to this as a type b slab. Determine the loads based on the buildings parameters section d. Empirical method a method of design and analysis based on a nationally approved or equivalent standard may be used to design slabs on grade. Subgrade for concrete slabs is the natural ground, which is typically prepared by grading and compaction. The use of welded wire reinforcement in concrete has a long. There are two types of concrete mixes, nominal mix and design mix. Develop and report on criteria for design of slabs on grade, except highway and airport pavements 1. Curling is the distortion of a slab into a curved shape by upward or downward bending of the edges. Design of slabs on grade aci 360r92 by american concrete institute from aci manual of concrete practice, 1999 4. Nov 12, 2018 before casting slab on grade, the earth is excavated up to the required depth and compacted to expel air voids.
These boards act as a concrete mould, which helps in identifying slab corners. Calculators for structural engineers, construction professionals and steel building specifiers. Reinforced and prestressed concrete are used extensively in bridge projects. Design of slab for flexure 067 m unit width of slab. Reinforcing is added to control shrinkage cracking and maximize the distance between designed joints. In addition to general design guidance and information on detailing practices, this section contains three design examples. For slabs spanning in both directions published tables and charts should be used to find bending moment and shear per unit width of slab. A 2 2area 2 a c 2 2 posttensioned concrete design table 11 list of symbols used in the aci 31808 code cp area enclosed by the outside perimeter of the section, in a g gross area of concrete, in a 2 l total area of longitudinal reinforcement to resist torsion, in a o area enclosed by the shear flow path, sqin a oh area enclosed by the centerline of the outermost closed. In general, characteristics of the concrete slab surface and joint. Concrete slab on grade analysis calculator for post or. In most cases, the slab thickness is designed as an unreinforced concrete section. Accurate concrete mix design makes concrete construction economical.
Reinforced concrete design 1 design of slab examples. The reinforced concrete design manual sp1711 is intended to provide guidance and assistance to professionals engaged in the design of castinplace reinforced concrete structures. Design is defined as the decisionmaking process of planning, sizing, detailing, and developing specifications preceding construction of slabs on ground. The occurrence is primarily due to differences in moisture andor temperature between the top and bottom surfaces of a concrete slab. This manual prescribes the criteria for the design of concrete floor slabs on grade in buildings for heavy loads and is applicable to all elements. Portland cement association skokie, il abstract various types of concrete slab track are in service in japan, europe and north america. Pdf a new method for designing floor slabs on grade due to the. April 2008 discussions on design issues for structural engineers. Slab thickness design for industrial concrete floors on grade is195. Asce, secb course content slab on grades construction. Guide for concrete floor and slab construction aci 302. Nominal mix concrete are those which are generally used for small scale construction and small residential buildings where concrete consumption is. The slab is outside buildings which subjected to 1 hr fire resistance and design for 50 years design life. On site concrete slab on grade construction this most often occurs in areas where the ground is not subject to freezing and therefore not likely to heave.
This section covers below grade construction details that apply to all building types, for either combustible or noncombustible construction classifications. Figures 5 and 6 show concrete masonry stemwalls with masonry and with frame above grade walls, respectively. The first reinforced concrete design manual formerly titled aci design handbook was developed in. Design of slabs on grade aci committee was specifically charged to cover design. Grdslab concrete slab on grade analysis spreadsheet. Manual for design and detailing of reinforced concrete to the september 20 code of practice for structural use of concrete 20 2. The construction and design of concrete slabs on grade. The slab is outside buildings which subjected to 1 hr fire resistance and design. Concrete is a composite mixture which consists of cement, sand and aggregate. The design and construction of concrete slabs for parking lots and outside storage areas share many similarities with the design and construction of streets and highways, but they also have some. This guide identifies the various classes of floors based on use, construction design details, necessary site preparation, concrete type, and other related materials.
Tm 580912 concrete floor slabs on grade subjected to heavy. Slab thickness design for industrial concrete floors on grade. Slab on grade foundations are concrete slabs poured directly on the ground with no space between the ground and the concrete. For 1m slab width, moment, shear force, oneway continuous slab for continuous slab, moment and shear force can be obtained from table 3. The slab thickness depends on the type of loads on the floor slab. Design concrete slab on grade concrete engineering. Oftentimes use grade beams or thickened slabs on grade. A3 design examples using coe charts a4 slab design using posttensioning a5shrinkagecompensatingconcreteexamples chapter lintroduction l. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design.
Concrete slab on grade analysis the engineering community. Manual for design and detailing of reinforced concrete to the. The primary design issues for stiffened slabs on grade are the sizing of the beams. It was concluded that designing plain concrete slabs without reinforcement on grade according to pca and the wri methods leads to slab fatigue, even though. The design procedure includes determini ng slab thickness based.
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