1/29/2024 0 Comments Worktime with self leveling grout![]() For instance, when the unit strength method is used to determine the specified compressive strength of the masonry, f’ m, Specification for Masonry Structures (ref. While 2,000 psi (13.79 MPa) is the minimum compressive strength required by ASTM C476, project requirements may require higher strengths. The grout proportions used to produce a grout with acceptable physical properties are then used to produce the grout for the project. It must also be mixed to a slump of 8 to 11 in. 5) and have a minimum compressive strength of 2,000 psi (13.79 MPa) at 28 days. When using the specified compressive strength method in ASTM C476, the grout must be sampled and tested in accordance with ASTM C1019 (ref. ![]() Using the proportions specified in Table 1 is a simple way to demonstrate compliance with ASTM C476. Written acceptance of grout mix submittals is required prior to the commencement of grouting operations (ref. Grout ProportionsĪSTM C476 allows grout mixtures to be determined either by compliance with the proportions listed in Table 1 or by those established through compressive strength testing. 1) for more information on grout space requirements and grout type selection. Coarse grout is typically more economical to produce. The choice of grout type therefore depends primarily on the minimum clear dimensions of the grout space, the grout pour height and construction economics. These requirements prescribe minimum and maximum aggregate sizes and a minimum grout compressive strength of 2,000 psi (13.79 MPa).īuilding codes and ASTM Specifications do not recognize any appreciable compressive strength difference between fine and coarse grouts. When an aggregate does not meet the ASTM C404 grading requirements, it may still be used provided the requirements of ASTM C404 section 4.2 are met. 4), which includes requirements for grading, impurities, soundness, and methods of aggregate sampling and testing. (13 mm), or other acceptable aggregate, in addition to the sand.Īggregates for grout must comply with ASTM C404, Standard Specification for Aggregates for Masonry Grout (ref. (9.5 mm) as its only aggregate, while coarse grout allows pea gravel smaller than ½ in. Fine grout contains sand smaller than ⅜ in. ASTM C476 defines two types of grout: fine and coarse. 3), or the governing building code which may permit grouting options other than those in set forth in ASTM C476. Grout for use in concrete masonry construction should comply with ASTM C476, Standard Specification for Grout for Masonry (ref. Information on grout mixing and placement and on grout testing is contained in Grouting Concrete Masonry Walls, TEK 3-2A and Grout Quality Assurance, TEK 18-8B (refs. This TEK includes information about: types of grout grout properties grout admixtures and self consolidating grout. Reinforced masonry construction, however, requires grout to be placed around the reinforcement. Grouted masonry construction is not required to be reinforced, but typically is for design economy. Masonry cantilever retaining walls are often solidly grouted to increase the wall’s weight, and hence resistance to overturning. Grouted cores also increase the net cross-sectional area of concrete masonry and permit walls to carry higher compressive, shear loads and lateral loads. Composite walls consist of two wythes of masonry with a solidly grouted collar joint with or without reinforcing steel. The most common example is in reinforced construction, where grout bonds the steel reinforcing bars to the masonry, allowing them to act as one system in resisting loads. Generally, grout is used to structurally bond wall elements into a wall system. The final water-to-cement ratio is significantly reduced, thus grout develops high compressive strength despite its apparent high initial water to cement ratio. The high initial water content of typical grout mixes compensates for water absorption by the masonry during and after grout placement. With approval, admixtures may be added to the grout mix. Grout is composed of cement, aggregate, lime (optional) and sufficient water to allow ease of placement and ensure complete filling of the grout space. While usually added for structural reasons, grout can also increase: fire ratings, security, acoustical performance, termite resistance, blast resistance, thermal storage capacity and anchorage capabilities. Masonry grout is a cementitious mixture used to fill cores or cavities in masonry construction.
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