Spall-Resistant Cementitious Material

Abstract

Disclosed is an essentially shaped cementitious product wherein the direct tensile strength of the product as determined by ASTM C307 is at least 120% of a predicted direct tensile strength of the product per an equation selected from the group consisting of f′dt=0.06*f′c, f′dt=0.07*f′c, f′dt=0.08*f′c and f′dt=0.11*f′c, and wherein the flexural strength of the product as determined by ASTM C348 is at least 150% of a predicted flexural strength of the product per an equation selected from the group consisting of f′r=0.1*f′c, f′r=0.17*f′c, f′r=9.5*((f′c)̂0.5) and f′r=7.5*((f′c)̂0.5).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61 / 702,404, filed on Sep. 18, 2012, in the name of the present inventor, this provisional application being incorporated herein by reference.FIELD OF THE INVENTION[0002]The field relates to a cementitious material that possesses favorable toughness and resists spalling.BACKGROUND OF THE INVENTION[0003]There is a long-felt need for a cementitious material having sufficient strength while also possessing favorable toughness. Typically, overall strength decreases, with one example being compressive strength, while toughness increases. Strength is defined as force per unit area, i.e. energy per unit volume, while toughness is energy per unit area.[0004]The toughness index, as evaluated by the area under the load-deflection curve, is considered as a measure of the energy absorption capability of the material during fracture i...

AI Technical Summary

Benefits of technology

This patent describes a material made of cement and latex polymer that can be used in a variety of applications, such as construction. The material has improved strength and durability, and can withstand blast or ballistic impacts. The material can be formed into various shapes and can be used as a coating, a covering, or a filling material. The strength of the material can be improved by adjusting the ratio of polymer to cement. The material has a unique structure that allows it to absorb energy and deform without breaking. The material has been tested and shown to have good strength and durability.

Problems solved by technology

The densified spacing packing “DSP” based cementitious materials are however distinctly brittle, the more so the higher the compressive strength.

In fact, although the tensile strength is about one tenth of the compressive strength, the material is intrinsically brittle.

Such behavior of polymeric material has the potential to lead to creep type behavior for select mix designs.

High polymer / cement ratio materials often display a longer plateau for the yield curve as the material fails and the platens of the testing machine move a greater distance during failure when compared with materials more brittle in nature.

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