Hydraulic-Press Brick Co. / Expanded Shale Institute commemorative plaque

Object/Artifact

National Building Arts Center

Front of HPB / Expanded Shale Institute commemorative plaque

Front of a grey, brown, and gold commemorative plaque, with gold lettering and showing some scratches on the plaque's surface.

Name/Title

Hydraulic-Press Brick Co. / Expanded Shale Institute commemorative plaque

Description

A grayish, speckled concrete/shale sheet with a brown and gold metal plaque affixed, with gold lettering denoting the membership of the Hydraulic-Press Brick Co. with the Expanded Shale Institute (later the Expanded Shale Clay and Slate Institute), and the signatures of the president and director of the Expanded Shale Institute.

Use

Promotional object, used to commemorate the certification of the Hydraulic-Press Brick Co. as a charter member of the Expanded Shale Institute.

Collection

Promotional object displays

Made/Created

Date made

circa 1952

Time Period

20th Century

Notes

The Expanded Shale Clay and Slate Institute was formed in the spring of 1952, and HPB is a "charter member" that joined the institute in a meeting that established the institute as a functional non-profit. Thus, it can be assumed that this plaque was manufactured sometime in early 1952 and then presented to HPB at, or directly after, that spring 1952 meeting.

Lexicon

Nomenclature 4.0

Nomenclature Primary Object Term

Plaque

Nomenclature Sub-Class

Organizational Objects

Nomenclature Class

Ceremonial Objects

Nomenclature Category

Category 08: Communication Objects

Getty AAT

Concept

terrazzo

LOC Thesaurus for Graphic Materials

Concrete products industry

Dimensions

Height

17.5 cm

Width

24.3 cm

Depth

2.6 cm

Parts

Count

Parts

Plaque

Materials

Material

Terrazzo, Metal

Material Notes

May not be terrazzo exactly, but the body of the plaque is made of some kind of concrete with stone or slate pieces mixed throughout. The brown plaque in the middle is made of metal.

Color

Gray, Gold, Brown

Condition

Overall Condition

Good

Condition Type

Chip / Chipping, Scratch, Adhesive Residue

Date Examined

Jul 22, 2026

Examined By

Elena Marshall

Surface

In good condition, but the concrete body of the plaque has a few chips on the corners, while the brown metal plaque in the middle has some scratches. The back of the plaque has two spots at the top where there is some yellowed, resinous adhesive that has hardened and stuck to the concrete material of the plaque.

Research Notes

Research Type

Researcher

Person

Elena Marshall

Date

Jul 22, 2026

Web Links and URLs

Link to a PDF of a book on the history, applications, and economics of lightweight concrete, written by the Expanded Shale, Clay, and Slate Institute (originally the Expanded Shale Institute), which lists HPB as a member.

Notes

(See Made/Created) "In the Spring of 1952, acting on the invitation of a producer active in the field, expanded shale producers from the United States and Canada met in St. Louis to discuss a plan to form an organization of producers. The meeting resulted in the formation of the Expanded Shale Clay and Slate Institute as a non-profit, technical organization supported by the producers of expanded shale, clay or slate by the rotary kiln process" (Page 12).

Create Date

July 22, 2026

Update Date

July 22, 2026