Graphical Handbook for Reinforced Concrete Design by John Hawkesworth presents a method of working with reinforced-concrete calculations through plotted curves. Published in New York by D. Van Nostrand Company in 1906, it combines descriptions of plates, examples of their use and an appendix explaining the underlying assumptions.
A graphical approach to repeated calculations
Hawkesworth’s preface explains that the plates cover slabs, beams and columns under different loading conditions. His aim is to reduce repeated computation while preserving a choice of proportions of steel and concrete. The intended reader is already engaged in architectural or engineering work.
The introduction makes clear that the handbook belongs alongside broader study of reinforced concrete. Its graphical method is not presented as a complete introduction to every form of construction. Understanding the assumptions is necessary to appreciate what the curves mean.
For a historical engineering collection, the book is an instructive example of calculation aids before electronic tools. A plotted relationship can organize a family of problems, but the user still has to select the right conditions and interpret the result correctly.
Slabs, reinforcement spacing and footings
The opening plates address a constant used in determining resisting moments, then the design of slabs under different conditions of span and loading. Each plate is accompanied by a description and practical examples, so the reader can connect the graph with the quantities in a problem.
Another plate concerns the spacing of square bars needed to obtain a given metal area per foot of width. Footing slabs are treated through external bending moments associated with column loads. These topics show how a graphical tool was used for both the concrete section and its reinforcement.
The arrangement is useful for researchers examining older office practice. It demonstrates the movement between a structural question, a numerical quantity and a drawing or graph, rather than treating design as a single formula applied without context.
Beams, neutral axes and shear
Further plates give resisting moments for different depths of beams or slabs and convert reinforcement areas between widths. The location of the neutral axis is considered separately. Shearing resistance is presented for combinations of concrete and steel.
These sections reveal the mechanical model behind the method. The variables are connected, and changing a section or reinforcement quantity affects more than one part of the calculation. The worked uses help explain how Hawkesworth expected the plates to be read.
Readers studying the history of structures can compare this organization with the way the same subjects are taught in later texts. The book preserves a particular set of assumptions and allowable stresses, rather than a timeless method that can be applied unchanged.
Columns and a complete example
Square and rectangular columns receive their own plates. Hooped columns with six or eight longitudinal members follow. The text then develops a complete design of a reinforced-concrete structure, with a plate illustrating the example.
This complete example gives the separate tools a common setting. It allows the reader to see how individual calculations were assembled into a larger design process. That is especially helpful when interpreting plates that might otherwise appear as disconnected reference sheets.
The column material and complete example belong to the book’s historical regulatory environment. They should not be treated as approved designs for a present-day building or as a substitute for structural assessment.
The appendix and historical regulations
The appendix states preliminary hypotheses and discusses rectangular members, T beams, direct compression and hooped columns. It also reproduces regulations of the New York Building Code. The preface identifies that code’s unit stresses as the standard adopted for the handbook.
This makes the appendix central to interpretation. The curves depend on chosen limits and models, and the regulatory material explains part of that choice. Current design requires current codes, evidence and professional judgment.
Audience and scan navigation
This free ebook suits engineering historians, architectural researchers and readers interested in graphical calculation. The PDF contains 98 digital pages, including the original dark cover, preliminary matter and plates. Searchable text is available, but small labels and symbols can be misrecognized. Use the contents to locate a plate’s explanation and compare it with the scanned graph before interpreting any value.
Book details
- Author: John Hawkesworth
- Publisher: D. Van Nostrand Company, New York
- Year: 1906
- Edition: No numbered edition stated
- Digital length: 98 PDF pages
- Language: English
- File size: 4.98 MB
