This document summarizes research on using structural polymer concrete (SPC) to strengthen and stabilize concrete structures. SPC has mechanical properties 4-5 times stronger than ordinary concrete, with higher elastic modulus and complete waterproofness. The document outlines SPC characteristics and provides examples of how it can reinforce beam-column connections in seismic areas. It also summarizes experimental testing of SPC samples that showed high compressive strength even after only 24 hours. The researchers aim to develop design standards for using SPC to modify structural diagrams and add seismic dampers at connections.
3. AllphotosillustredarecopiedfromtheWEB
(a) (b)
The two photos illustrate the activation of the "soft floor" in buildings subject to different entities seismic
mechanism:
- Building (a) earthquake of magnitude 6.5 on the Richter scale;
- Building (b) earthquake of magnitude 6.2 on the Richter scale.
4. AllphotosillustredarecopiedfromtheWEB
(a)
(b)
(a) and (b) illustrate the collapse in the upper part of the pillar.
Vertical descensons in heads of walls with possible disappointments that
translate into horizontal displacements at higher levels, greater than one
per thousand, maximum consensus value.
6. Particular "A"
“A”
STRUCTURAL POLYMER CONCRETE - SPC
STUDY CONCERNINGNG PLANNING CRITERIA TO REINFORCE THE BEAM-COLUMN KNOTS IN SEISMIC AREAS WITH
”STRUCUTURAL POLYMER CONCRETE - SPC”
7. Particular "A"
STRUCTURAL POLYMER CONCRETE
EXAMPLE OF CASTING DISTRIBUTION WITH STRUCTURAL POLYMER CONCRETE-SPC WITHOUT USING STRONG
REINFORCEMENT AS PRESCRIBED BY “ACI 352” CAUSING SEVERAL DIFFICULTIES ISTHE EXECUTION
EXAMPLE OF A CONSTRUCTIVE DETAIL
This study intends to stimulate the development of a new material. There are nanely several reasons to consider the “Structural
Polymer Concrete-SPC” a new material, even if same ins not causing a revolutonary follow-up.
This statement is due to the fact that the stress breaking point is 4 to 5 times higher than that of the ordinary concrete.
Furthermore it has a doubling of the elstic modulus and it is completely watertproof and unalterable by atmospheric agents.
8. FIG. 1
EXAMPLE OF STRESS DISTRIBUTION INTHE
REINFORCEMENTS AND INTHE CONCRETE
INTHE BEAM-COLUMN CONNECTION AREA
Owing to this it is important to write a complete and reliable advice,
suplemented with both experimental and theoretical probings.
A normal concrete usually reaches after hardening an average mechanical
compressive strength of about 400 kg/cm2 , and seldom more than 600
kg/cm2 . On the contrary a special “Structural Polymer Concrete-SPC” , may
have a strength of about 1200 kg/cm2. Furthermore with special devices in
the aggregates, the figures of compressive strength may reach nearly 3000
kg/cm2.
Also tensile strength increase from about 30/40 kg/cm2 of the normal
concretes to about 200/500 kg/cm2.
For what concerns other characteristics: in the “Structural Polymer Concrete -
SPC” there is no water absorption, therefore it has a nearly total frost
resistance.
Upon examining the properties of the “structural concrete” it is evident that its
utilization concerns, above all, those applications where traditional concretes
do not give satisfactory results to comply with the needs of the building
techniques and the purposes of the work to assure sufficient stiffness,
resistance and ductility levels as well as capability of energy dissipation for
what concerns seismic problems.
Regretfully, today “structural concretes” are not so frequently used, both for
the scarse knowledge of non-traditional products, and for a mistrust often due
to prejudice and mostly unjustified commonplaces.
9. FIG. 2
EXAMPLE OF SHEAR STRESS ON A BEAM-COLUMN KNOT
After the above necessary forword, it is time to illustrate the peculiarities of the “Structural Polymer Concrete-SPC”, as wellas its
antiseismic reinforcement and adaptation features, for what concers both economy and safety problems.
The discussion more than dealing about calculations, will particularly revert on the application procedures and the building details
involved. This is due to the fact that good behaviour under the action of an earthquake is not due to accurate calculations, but mainly
to the careful study of certain “details” and to the material responsible for the antiseismic safety.
Main characteristics of the “Structural Polymer Concrete- SPC” for its structural use are the following:
- Good workability;
- Thixotrophic properties;
- Hardening or polymerization process undependent on temperature or humidity;
- Low shrinkage and viscosity phenomena and consequent lack of cracks;
- Characteristics of mechanical influences not influenced by any ageing or alternating stress process;
- Nearly total reduction of water permeability or absorption, therefore exceptional resistance to frost and aggressive agents of any
kind;
- Adhesion iron/reinforced concrete increased of about 4 times the values of the ordinary reinforced concrete.
10. All these characteristics are to be included in a complete and articulated frame, like the standards to calculate the limit states of the normal
and prestressed concrete.
The “Structural Polymer Concrete-SPC” is a non-traditional concrete where the binding function is not done by cement but by thermosetting
synthetic resins . This can produce some structural reinforcement “details”, in causing a seismic matching of the work completely modifying
the stativ diagram and building, while working, some “dissipators” at the beam-column knots.
The dimensioning of this kind of interference has to be done according to the instructions of stress trasmission inside the knots (fig. 1 and 2):
that is to say in a rather wide area to avoid stress concentration in correspondence of the linkage knots of beams and pillars.
Furthermore, wile making the project, it is necessary to verify the difference between the mechanical and deforming characteristics of the two
materials in contact, that have been cast at different times. One has to keep in mind that this kind of interference cannot be codified, not only
to standardize it as it concerns the use of materials with peculiar characteristics, which efficacy has to be absolutely guaranteed. And there is
also to consider the fact that this kind of interference has a high percentace of costs.
It is necessary to study and experiment materials and components and inform of any result all those involved in the project, keeping in mind at
the same time thath wrong or wrongly known results may be damage to the community.
This subject is of great interest first of all to planners, chief engineers, testing surveyors and consignors involved in earthquake problems.
It is necessary, as indicated in our vorword, to succeed in obtaining coditied standars to apply easily, to use them to prepare specifications and
technical cars of materials and components to guarantee tha the excution of works will be technically reilable.
To answer allthis, it is necessary to effect a deep survey to satisfy the chamge demand to all technical problems to obtain good quality in
works. On our part, we realize we are not well prepared also for what concerns the skillfullness of the workers who need to be well
experienced in dealing with these materials: the thermosetting synthetic resins, a hard and always new field.
11. TAB. 1
MECHNICAL STRENGTH CHARACTERISTICS OFTHE
“STRUCTURAL POLYMER CONCRETE- SPC”
In my opinion this problem has to be dealt with the utmost care and seriousness, in promoting enterprises tending to qualify
both technicians and building contractors.
COMPRENSIVE STRENGTH DIN 1164 120 N/mm2
FLEXURAL STRENGTH DIN 1164 30/80 “
TENSILE STRENGTH DIN 53445 15 “
ELASTIC MODULUS DIN 53457 7000 “
CRACKING ELONGATION DIN 53445 6,7 “
ADHESIVE PROPERTIES ORDINARY CONCRETE STRUCTURAL AND STRUCTURAL POLYMER CONCRETE-SPC
It is very important to point out the influence and employ possibilities due to the adhesive properties of polymer concretes on the
ordinary concrete.
Polymer concretes can WET surfaces of ordinart concrete, and another facot to remember is that polymer chemistry has given origin to
a rich series of adhesive materials. They vary conspicuously according to the inert charges, without causing SALACKERING.
12. EXAMPLE OF BEHAVIOR OF THE ”NODES” BEAM-COLUMN
(a1) armed node according to legislation;
(a2) node with reduced confinement;
(b) a constructive detail of external node
with additional inclined armor;
(c) external node response with inclined
armor;
(d) Reinforced external node response in
conventional manner.
13. (a) (b) (c)
(d) (e)
TYPE OF COLLAPSE INTO NODES "BEAM-COLUMN":
a) - the achievement of the bearing capacity of the beam;
b) - attainment of the load-bearing capacity in the column;
c) - expulsion of the concrete cover in the node;
d) - the collapse for anchoring of the reinforcement beam;
e) - to collapse the node cut.
AllphotosillustredarecopiedfromtheWEB
17. DETERMINATION OFTHE SHARES IN "NODES"
a) – Forces acting on
the column
b) – Bending
moments
c) – Sheor
forces
d) – Crack
patterns
e) – Variation of internal
tension forces along
the column
21. DESTRUCTIVE TESTING PERFORMED ON SAMPLES OF “STRUCTURAL POLYMER CONCRETE-SPC”
Dimension sample of "Structural
Polymer Concrete -SPC" 4x4x4 cm
MECHANICAL RESISTANCE TEST
Sample of "Structural Polymer Concrete -SPC" subjected to compression test in
the laboratory after only 24 hours from its mixing.
22. Mix study of the aggregates for the “SPC” samples to be
subjected in the laboratory to mechanical resistance tests
Samples of “SPC” (measuring 4x4x16 cm and 4x4x4 cm)
to be subjected in the laboratory to mechanical resistance
tests: compression, direct tensile and flexural.
Visual assessment on the "fluidity"
and "flowability" of the “SPC”.
23. AnnaLaura Bellicini
Architect
Graduated in architecture at the University "La Sapienza" of ROME (ITALY), regularly registered in the professional, carries out
independent professional activities.
From the outset has developed career path focused on the study and design of interventions that employ advanced technologies and
innovative materials.
Has experienced collaborators of professionals, technicians, consultants, production companies and executing, it provides specific
solutions for the consolidation and rehabilitation of buildings and civil structures.
e-mail: belliciniannalaura @ gmail.com
24. INDEPENDENT CONSULTANT TUNNELING , MINING AND OIL
SPECIALIZED IN MECHANIZED TUNNELING WITH HARD ROCK
TBM AND SOFT SOIL EPB SHIELDS
EXPERT AND CONSULTANT IN STRUCTURAL REINFORCEMENT
LAMANNA Luigi Franco, performs for 45 years professional consulting and technical direction in the various sectors
of civil, industrial, military, hydraulics, railway, highway and recent years in the sector of “tunneling” and “mining” on
the correct use of special “resin” and related technologies for consolidation, repair and maintenance of masonry,
concrete, iron and wood.
Is the author of numerous scientific publications and is always engaged in the study and development of “innovative
materials” and related techniques and technologies used.
e-mail: lamannaluigifranco1 @ gmail.com
25. - MAINTENANCE OF AIRPORT PAVEMENTS, ROAD TRANSPORT AND CONDUCTIVE/DISSIPATIVE
PAVEMENTS
- INJECTION RESINS SYSTEM IN TUNNELLING, MINING AND CIVIL ENGINEERING
- DAMS and BRIDGS - REPAIR, PROTECTION AND REINFORCEMENT OF STRUCTURAL
CONCRETE
- SOLUTIONS FOR PRE-EXCAVATION GROUTING IN ROCK TUNNELING AND MINING
AllphotosillustredarecopiedfromtheWEB
26. LIBERATORIA
Questo PDF è un prodotto amatoriale al quale non può essere applicato l'art. 5 della legge italiana 08 Febbraio 1948 n. 47, poiché l'aggiornamento
delle notizie in esso contenute non ha periodicità regolare (art. 1 comma 3, legge 07 Marzo 2001 n. 62).
Questo PDF non rappresenta una testata giornalistica o quant’altro e i post editi hanno lo scopo di stimolare la discussione e l’approfondimento
tecnico, la critica e la libertà di espressione del pensiero, nei modi e nei termini consentiti dalla legislazione italiana vigente.
Come a conoscenza in tutto il mondo il materiale pubblicato su Internet è di dominio pubblico. Tuttavia, se qualcuno riconoscesse proprio
materiale con Copyright e non volesse vederlo pubblicato su questo PDF, non ha che da darne avviso al gestore e sarà immediatamente
eliminato.
Dichiariamo, inoltre, di non essere responsabili per i commenti inseriti nei post. Eventuali commenti dei lettori, lesivi dell'immagine o dell'onorabilità
di persone terze, non sono da attribuirsi a noi, nemmeno se gli stessi vengono espressi in forma anonima o criptata.
DISCLAIMER
This PDF is an amateur product which can not be applied Article. 5 of the Italian Law No 8 February 1948 n. 47, since the updating of the information
contained in it has no regular periodicity (art. 1 paragraph 3, of the law 7 March 2001 n. 62).
This PDF is not represent a journalistic head or whatever and posts published are intended to stimulate discussion and the technical study, criticism
and freedom of expression of thought, in the manner and within the terms permitted by current Italian legislation.
How known all over the world the material published on the Internet is public domain. Nevertheless, if someone would recognize their own material
with Copyright and did not want see it published on this PDF, it only has to give notice to the manager and will be immediately eliminated.
We declare, moreover, they are not responsible for the comments included in the post. Any reader comments, damaging the image or repute of
third persons, are not to be attributed to us, not even if these are expressed in an anonymous or encrypted.